Extended-spectrum beta-lactamase-producing Escherichia coli from pork in Muang district, Chiang Mai Province, Thailand

Research (Published online: 21-12-2022)

19. Extended-spectrum beta-lactamase-producing Escherichia coli from pork in Muang district, Chiang Mai Province, Thailand

Wirunchana Srichumporn, Warangkhana Chaisowwong, Montira Intanon, and Kannika Na-Lampang

Veterinary World, 15(12): 2903-2909

ABSTRACT

Background and Aim: Contaminated pork is one of the transmission routes for pathogens. Extended-spectrum beta-lactamases (ESBL)-producing Escherichia coli is one of the critical threats to global public health. This study aimed to examine pork from different types of markets in Muang district, Chiangmai Province, Thailand, for a proportion of ESBL-producing E. coli, antibiotic resistance of ESBL-producing E. coli and ESBL-producing E. coli genotypes.

Materials and Methods: Samples were collected from different market types; fresh markets, pork stores, and supermarkets, enriched and inoculated on selective media. Extended-spectrum beta-lactamases-producing E. coli was identified using double-disk diffusion method according to Clinical and Laboratory Standards Institute 2016. Antibiotic susceptibility test was performed through VITEK® System and ESBL-encoding genes were detected using a multiplex polymerase chain reaction.

Results: About 69% of the samples were positive to ESBL-producing E. coli and showed high rates of resistance for ampicillin (100%), piperacillin (100%), cefalexin (100%), cefpodoxime (100%), cefovecin (100%) and ceftiofur (100%), gentamycin (89.86%), and tetracycline (TE) (84.06%). All isolates were multiple drug resistant; resistance patterns of beta-lactams, aminoglycosides, TEs, nitrobenzene derivatives, and sulfonamide groups were observed. The ESBL-producing E. coli-positive isolates carried blaCTX-M groups (100%), blaTEM (98.55%), and blaSHV (1.45%). None of blaOXA was found in this study.

Conclusion: Extended-spectrum beta-lactamases-producing E. coli was found in various types of markets; all isolates were detected as multidrug-resistant. The dissemination of such strains can conceivably cause concerning public health, implying that supervised antimicrobial use in pork production and sanitary food preparation is recommended.

Keywords: antimicrobial resistance, extended-spectrum beta-lactamases-producing Escherichia coli, pork, Thailand.

Toxicity test of flavonoid compounds from the leaves of Dendrophthoe pentandra (L.) Miq. using in vitro culture cell models

Research (Published online: 21-12-2022)

18. Toxicity test of flavonoid compounds from the leaves of Dendrophthoe pentandra (L.) Miq. using in vitro culture cell models

Mochamad Lazuardi, Suharjono Suharjono, Chi-Hsien Chien, Jie-Long He, Chi-Wen Lee, Chia-Kang Peng, Mohammad Sukmanadi, Rahmi Sugihartuti, and Lilik Maslachah

Veterinary World, 15(12): 2896-2902

ABSTRACT

Background and Aim: The flavonoids from mistletoe are thought to have antimicrobial action. This encouraging finding supports the benefits of medicinal plants as a substitute for synthetic antimicrobials, thus promoting healthy lifestyles. In contrast, it is known that the use of topical drug formulations made from flavonoids of mistletoe (Dendrophthoe pentandra (L.) Miq. Loranthaceae) with Indonesian name, Benalu duku (BD) is required in skin cell irritation. This study aimed to assess the toxic effects of the flavonoid substances of BD, as an initial screening.

Materials and Methods: A myeloma cell line was cultured in Roswell Park Memorial Institute medium, and the Baby Hamster Kidney clone 12 (BHK21) cell line was cultured in Dulbecco's Modified Eagle's Medium from stock (±9 × 107 cells/mL), and 1.2 mL of culture were distributed into each well of a microtiter plate. Subsequently, 0.2 mL of serially diluted flavonoid compounds (0.5–3 μg/mL) were added to 12 wells for each concentration, as trial groups (including control groups), followed by a 2-day incubation. Observations were performed based on the cytopathic effect (CPE) using an inverted microscope at a magnification of 100×.

Results: Cytopathic effect was detected on the microtiter plate wells for the groups of myeloma and BHK21 cells at a flavonoid concentration of 0.5 μg/mL–3 μg/mL.

Conclusion: Flavonoid compounds from BD were safely used for topical treatment of cancer cells at a concentration <2.491 μg/mL, whereas for non-cancerous cells, a concentration <2.582 μg/mL was sufficient (p < 0.05).

Keywords: antimicrobial, Baby Hamster Kidney clone 12 cell culture, cytopathic effect, healthy lifestyle, myeloma cell culture.

Effect of follicle-stimulating hormone and luteinizing hormone levels on egg-laying frequency in hens

Research (Published online: 20-12-2022)

17. Effect of follicle-stimulating hormone and luteinizing hormone levels on egg-laying frequency in hens

Ragil Angga Prastiya, Sri Pantja Madyawati, Sera Yunita Sari, and Aras Prasetiyo Nugroho

Veterinary World, 15(12): 2890-2895

ABSTRACT

Background and Aim: Gonadotropins, for example, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), are hormones that affect the reproductive process. In hens, optimal levels of FSH and LH can stimulate follicle growth fairly rapidly and thereby increase egg production through follicle development and increased ovulation. Follicle-stimulating hormone acts in the early stages of follicular growth, whereas LH acts on pre-ovulatory follicles. Normal follicular growth is the result of the complementary action of FSH and LH. Low FSH and LH levels result in the formation of follicles but a lack of egg production in chickens. This study aimed to investigate FSH and LH hormone levels from layer chickens with different egg-laying frequencies.

Materials and Methods: Fifty blood serum samples were collected from 54-week-old ISA brown strain hens that were divided into five groups (with 10 hens per group) as follows: Hens that lay eggs (i) every day, (ii) once every 2 days, (iii) twice every 3 days, (iv) 3 times every 4 days, and (v) hens that do not lay eggs. Follicle-stimulating hormone and LH levels were measured in samples using an enzyme-linked immunosorbent assay, and the data were analyzed using multivariate analysis of variance.

Results: Follicle-stimulating hormone levels were significantly associated with the frequency of egg laying in ISA brown strain hens (p < 0.05); the highest FSH level (869.005 ± 149.194 pg/mL) was found in hens that lay eggs every day. In contrast, the highest LH level (51.386 ± 2.410 mIU/mL) was found in hens that lay eggs every 2 days.

Conclusion: High level of FSH (869.005 ± 149.194 pg/mL) was associated with a high frequency of egg laying (every day) in ISA brown strain hens, and LH level of around 30.406 pg/mL was associated with daily egg laying in these hens.

Keywords: egg-laying frequency, enzyme-linked immunosorbent assay, gonadotropin hormone, laying hens, reproductive health.

Molecular detection and phylogeny of Ehrlichia canis and Anaplasma platys in naturally infected dogs in Central and Northeast Thailand

Research (Published online: 20-12-2022)

16. Molecular detection and phylogeny of Ehrlichia canis and Anaplasma platys in naturally infected dogs in Central and Northeast Thailand

Andaman Purisarn, Sakulchit Wichianchot, Cherdsak Maneeruttanarungroj, Bandid Mangkit, Wuttinun Raksajit, Sarawan Kaewmongkol, Thitichai Jarudecha, Wanat Sricharern, and Rucksak Rucksaken

Veterinary World, 15(12): 2877-2889

ABSTRACT

Background and Aim: Ehrlichia canis and Anaplasma platys are tick-borne, Gram-negative bacteria that cause canine monocytic ehrlichiosis and canine cyclic thrombocytopenia, respectively. These diseases are of great importance and are distributed globally. This study aimed to create new primers for the identification of E. canis and A. platys in naturally infected dogs using polymerase chain reaction (PCR), DNA sequencing, and phylogenetic analysis using the 16S rDNA and gltA genes.

Materials and Methods: In total, 120 blood samples were collected from dogs in three different locations (Saraburi, Buriram, and Nakhon Ratchasima provinces) in Central and Northeast Thailand. The molecular prevalence of E. canis and A. platys was assessed using PCR targeting the 16S rDNA and gltA genes. All positive PCR amplicons were sequenced, and phylogenetic trees were constructed based on the maximum likelihood method.

Results: Ehrlichia canis had an overall molecular prevalence of 15.8% based on the 16S rDNA gene, compared to 8.3% based on the gltA gene. In addition, the overall molecular prevalence of A. platys using the 16S rDNA gene was 10.8%, while the prevalence rate was 5.8% using the gltA gene. Coinfection was 0.8% in Saraburi province. The partial sequences of the 16S rDNA and gltA genes of E. canis and A. platys in dogs in Central and Northeast Thailand showed 96.75%–100% identity to reference sequences in GenBank. Phylogenetic analysis of the 16S rDNA and gltA genes revealed that E. canis and A. platys sequences were clearly grouped into their own clades.

Conclusion: This study demonstrated the molecular prevalence of E. canis and A. platys in Central and Northeast Thailand. The 16S rDNA and gltA genes were useful for the diagnosis of E. canis and A. platys. Based on the phylogenetic analysis, the partial sequences of the 16S rDNA and gltA genes in E. canis and A. platys were related to prior Thai strains and those from other countries.

Keywords: 16S rDNA gene, Anaplasma platys, Ehrlichia canis, gltA gene, phylogenetic analysis.

Isolation of multidrug-resistant Escherichia coli and Salmonella spp. from sulfonamide-treated diarrheic calves

Research (Published online: 16-12-2022)

15. Isolation of multidrug-resistant Escherichia coli and Salmonella spp. from sulfonamide-treated diarrheic calves

Mohammad Amdadul Haque, Muhammad Tofazzal Hossain, Md. Shafiqul Islam, Md. Zahorul Islam, Purba Islam, Sourendra Nath Shaha, Mahmudul Hasan Sikder, and Kazi Rafiq

Veterinary World, 15(12): 2870-2876

ABSTRACT

Background and Aim: The bovine industry is threatened by one of the most serious and deadly enteric diseases, calf diarrhea, particularly in developing nations like Bangladesh. In this context, bacterial resistance to antimicrobial drugs and its detrimental consequences have become a critical public health issue that is difficult to address globally. This study aimed to isolate and identify Escherichia coli and Salmonella spp. with their antibiogram and antibiotic resistance gene detection from sulfonamide-treated diarrheic calves.

Materials and Methods: Twelve diarrheic calves suffering from calf diarrhea in a dairy farm were selected and a total of 36 fecal samples were aseptically collected directly from rectum before, during, and at the end of treatment for each calf to determine the total viable count, total E. coli count and total Salmonella count. A polymerase chain reaction was used for the specific detection of E. coli and Salmonella genus targeting fliC and invA genes, respectively. Antibiotic sensitivity test of the isolated E. coli and Salmonella spp. were performed by the disk diffusion method for eight commonly used antibiotics.

Results: A total of 36 E. coli (100%) and 12 Salmonella spp. (33%) were isolated from the samples and were confirmed by polymerase chain reaction. Total viable count was found to be ranged from 35 × 107 to 99 × 1010 colony-forming unit (CFU)/g fecal sample before starting sulfonamide treatment, 34 × 105 to 25 × 1010 CFU/g during treatment with sulfonamide, and 48 × 103 to 69 × 1010 CFU/g immediately after completion of sulfonamide treatment. Total E. coli count was found to be ranged from 4 × 104 to 36 × 1010 CFU/g, 24 × 104 to 23 × 108 CFU/g, and 13 × 104 to 85 × 1010 CFU/g, whereas total Salmonella count was found to be ranged from 16 × 106 to 18.5 × 1011 CFU/g, 15 × 104 to 44 × 107 CFU/g, and 13.2 × 105 to 21 × 1010 CFU/g fecal sample before starting sulfonamide treatment, during treatment with sulfonamide immediately after completion of sulfonamide treatment, respectively. The in vitro antibiotic sensitivity test showed that all the E. coli and Salmonella spp. isolated from diarrheic calves (100%) contained multidrug-resistant (MDR) phenotypes. Escherichia coli isolates were found 100% resistant to amoxicillin (AMX), cefuroxime, cephalexin (CN), erythromycin (ERY), and tetracycline (TET); whereas 94.4%, 86.1%, and 77.8% isolates were resistant to doxycycline (DOX), moxifloxacin (MOF), and gentamycin (GEN), respectively. In case of Salmonella isolates, all were found 100% resistant to AMX, CN, and ERY; whereas 91.7% of resistance was observed for DOX, MOF, cefuroxime, GEN, and TET. Based on the molecular screening of the antibiotic resistance genes, tetA gene was present in 83.3% of the isolated E. coli and 75% of the isolated Salmonella strains, whereas 83.3% E. coli and 79.2% Salmonella isolates contained blaTEM gene.

Conclusion: These findings suggest that MDR E. coli and Salmonella spp. might be responsible for calf scouring, which is challenging to treat with antibiotics or sulfonamide drugs alone. Therefore, it is important to check the antibiotic sensitivity pattern to select a suitable antibiotic for the treatment of calf scoring. A suitable antibiotic or combination of an antibiotic and sulfonamide could be effective against E. coli and Salmonella spp. responsible for calf scouring.

Keywords: antimicrobial resistance, calf, diarrhea, Escherichia coli, multidrug-resistant, Salmonella spp.

Selection and characterization of bacteriophages specific to Salmonella Choleraesuis in swine

Research (Published online: 16-12-2022)

14. Selection and characterization of bacteriophages specific to Salmonella Choleraesuis in swine

Pattaraporn Sriprasong, Napakhwan Imklin, and Rujikan Nasanit

Veterinary World, 15(12): 2856-2869

ABSTRACT

Background and Aim: Salmonella Choleraesuis is the most common serotype that causes salmonellosis in swine. Recently, the use of bacteriophages as a potential biocontrol strategy has increased. Therefore, this study aimed to isolate and characterize bacteriophages specific to S. Choleraesuis associated with swine infection and to evaluate the efficacy of individual phages and a phage cocktail against S. Choleraesuis strains in simulated intestinal fluid (SIF).

Materials and Methods: Three strains of S. Choleraesuis isolated from pig intestines served as host strains for phage isolation. The other 10 Salmonella serovars were also used for the phage host range test. The antibiotic susceptibility of the bacterial strains was investigated. Water samples from natural sources and drain liquid from slaughterhouses were collected for phage isolation. The isolated phages were characterized by determining the efficiency of plating against all Salmonella strains and the stability at a temperature range (4°C–65°C) and at low pH (2.5–4.0) in simulated gastric fluids (SGFs). Furthermore, morphology and genomic restriction analyses were performed for phage classification phages. Finally, S. Choleraesuis reduction in the SIF by the selected individual phages and a phage cocktail was investigated.

Results: The antibiotic susceptibility results revealed that most Salmonella strains were sensitive to all tested drugs. Salmonella Choleraesuis KPS615 was multidrug-resistant, showing resistance to three antibiotics. Nine phages were isolated. Most of them could infect four Salmonella strains. Phages vB_SCh-RP5i3B and vB_SCh-RP61i4 showed high efficiency in infecting S. Choleraesuis and Salmonella Rissen. The phages were stable for 1 h at 4°C–45°C. However, their viability decreased when the temperature increased to 65°C. In addition, most phages remained viable at a low pH (pH 2.5–4.0) for 2 h in SGF. The efficiency of phage treatment against S. Choleraesuis in SIF showed that individual phages and a phage cocktail with three phages effectively reduced S. Choleraesuis in SIF. However, the phage cocktails were more effective than the individual phages.

Conclusion: These results suggest that the newly isolated phages could be promising biocontrol agents against S. Choleraesuis infection in pigs and could be orally administered. However, further in vivo studies should be conducted.

Keywords: antimicrobials, bacteriophage, biocontrol, Salmonella Choleraesuis, swine.

Estimation of the herd-level basic reproduction number for African swine fever in Vietnam, 2019

Research (Published online: 15-12-2022)

13. Estimation of the herd-level basic reproduction number for African swine fever in Vietnam, 2019

Thi Ngan Mai, Thanh Trung Nguyen, Viet Anh Vu, Thi Ngoc Vu and Thi My Le Huynh

Veterinary World, 15(12): 2850-2855

ABSTRACT

Background and Aim: African swine fever (ASF) is a notifiable viral disease of pigs and wild boars that causes severe economic losses to the swine industry. The pig industry in Vietnam was recently attacked by the ASF virus (ASFV) for the first time in history. However, we lack information regarding the transmissibility of ASF within indoor production systems communities, such as those in Vietnam. Therefore, we aimed to estimate the basic reproduction number (R0) for ASF during the early stages of transmission between farms in indoor production system communities from local and national data in Vietnam.

Materials and Methods: The linear regression model approach for the susceptible infectious method was used in this study to estimate the transmission rate and, consequently, the R0 value.

Results: The R0 values between-farm of ASF ranged from 1.41 to 10.8 in different scenarios of infectious period duration, from 15 to 30 days at the national and local levels.

Conclusion: These results help to understand the scale and speed of ASF infection in Vietnam and to provide a scientific basis to implement control measures to restrict the spread of ASFV in other locations.

Keywords: African swine fever, basic reproduction number, indoor production, Vietnam.