Papers by Patchara Phuektes
Journal of Dairy Science, May 1, 2001
To improve diagnosis of mastitis in dairy cattle, a multiplex polymerase chain reaction (PCR) ass... more To improve diagnosis of mastitis in dairy cattle, a multiplex polymerase chain reaction (PCR) assay was developed for the simultaneous detection of the four major bacterial causes of bovine mastitis, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae, and Streptococcus uberis. The target sequence was the 16S to 23S rRNA spacer regions. The performance of the assay was examined with 117 milk samples collected from a subclinically infected herd, and the diagnostic specificities and sensitivities of the multiplex PCR were compared with conventional culture. PCR was significantly more sensitive than culture for detection of S. aureus and S. uberis, but there were no significant differences in sensitivities between PCR and culture for the detection of S. agalactiae and S. dysgalactiae. The results suggest that this multiplex PCR assay could be used as an alternative method in routine diagnosis for rapid, sensitive, and specific simultaneous detection of S. aureus, S. agalactiae, S. dysgalactiae, and S. uberis in milk samples.
Journal of Clinical Microbiology, Apr 1, 2001
Pulsed-field gel electrophoresis and antimicrobial sensitivity testing were used as tools to inve... more Pulsed-field gel electrophoresis and antimicrobial sensitivity testing were used as tools to investigate the epidemiology of Streptococcus uberis mastitis in dairy cows. A total of 62 different strains were found among 138 isolates from the four herds investigated, and between 10 and 26 different strains were found in each herd. There was no strain common to all four herds. Identical strains of S. uberis were detected from different quarters of individual cows and from cows within the same herd, suggesting that transmission from quarter to quarter and cow to cow had occurred. Despite the great variation in S. uberis strains, persistent infection with the same strain within a lactation was observed in most cows. Predominant strains were present in two herds. Preliminary investigations could not clarify why these particular strains might predominate, but in one herd there was a significant difference between the prevalence of clinical mastitis in quarters infected with the predominant strain and that in quarters infected with other strains, suggesting the greater virulence of the predominant strain. The wide variety of S. uberis strains found is consistent with an environmental source of S. uberis. However, evidence of direct transmission, the persistence of infection, and the predominance of particular strains in some herds indicate that S. uberis infections are epidemiologically complex and that the relative importance of these factors in the occurrence of mastitis may differ between herds.
Foodborne pathogens and disease, Mar 12, 2024
Journal of Virological Methods, Dec 1, 2010
Human enterovirus 71 (HEV71) and coxsackievirus A16 (CVA16) are two major aetiological agents of ... more Human enterovirus 71 (HEV71) and coxsackievirus A16 (CVA16) are two major aetiological agents of hand, foot and mouth disease (HFMD) in children. Recently there have been several large outbreaks of HFMD in Vietnam and the Asia-Pacific region. In this study, a multiplex RT-PCR assay was developed in order to detect simultaneously HEV71, CVA16 and other human enteroviruses. Enterovirus detection was performed with a mixture of three pairs of oligonucleotide primers: one pair of published primers for amplifying all known enterovirus genomes and two new primer pairs specific for detection of the VP1 genes of HEV71 and CVA16. Enterovirus isolates, CVA16 and HEV71 strains identified previously from patients with HFMD were examined to evaluate the sensitivity and specificity of the multiplex RT-PCR assay. The assay was then applied to the direct detection of these viruses in clinical specimens obtained from HFMD cases identified at Children's Hospital Number 2, Ho Chi Minh City, Vietnam. The multiplex RT-PCR assay showed 100% specificity in screening for enteroviruses and in identifying HEV71 and CVA16. Similar results were obtained when using the multiplex RT-PCR assay to screen for enteroviruses and to identify HEV71 and CVA16 in clinical specimens obtained from HFMD cases identified at the hospital. This multiplex RT-PCR assay is a rapid, sensitive and specific assay for the diagnosis of HEV71 or CVA16 infection in cases of HFMD and is also potentially useful for molecular epidemiological investigations.
Poultry Science, Oct 1, 2021
One hundred and twenty chicken samples from feces (n = 80), the carcass surface at slaughter at 2... more One hundred and twenty chicken samples from feces (n = 80), the carcass surface at slaughter at 2 meat chicken farms (n = 20), and retail chicken meat from 5 markets (n = 20) collected during 2018 and 2019 were examined for the prevalence of plasmid-mediated quinolone resistance (PMQR) in Escherichia coli. We detected qnrS-positive E. coli in a total of 74 samples from feces (n = 59), the carcass surface (n = 7), and retail meat (n = 8). These 74 qnrS-positive isolates were tested for antimicrobial susceptibility to determine the minimum inhibitory concentrations (MICs) of certain antimicrobials and genetically characterized. Ampicillin-resistance accounted for 71 of the 74 isolates (96%), followed by resistance to oxytetracycline (57/74; 77%), enrofloxacin (ERFX) (56/74; 76%), sulfisoxazole (SUL) (56/74; 76%), trimethoprim (TMP) (49/74; 66%), and dihydrostreptomycin (48/74; 65%). All farm-borne SUL- and TMP-resistant isolates except one were obtained from samples from farm A where a combination of sulfadiazine and TMP was administered to the chickens. Concentrations of ERFX at which 50 and 90% of isolates were inhibited were 2 μg/mL and 32 μg/mL, respectively. Diverse pulsed-field gel electrophoresis (PFGE) patterns of XbaI-digested genomic DNA were observed in the qnrS-positive isolates from fecal samples. Several isolates from feces and the carcass surface had identical XbaI-digested PFGE patterns. S1-nuclease PFGE and Southern blot analysis demonstrated that 7 of 11 dfrA13-positive fecal isolates carried both the qnrS and dfrA13 genes on the same plasmid, and 2 of 3 dfrA1-positive isolates similarly carried both qnrS and dfrA1 on the same plasmid, although the PFGE patterns of XbaI-digested genomic DNA of the isolates were different. These results suggest that the qnrS gene is prevalent in chicken farms via horizontal transfer of plasmids and may partly be co-selected under the use of TMP.
Journal of Veterinary Medical Science, 2018
The Thai Journal of Veterinary Medicine
This study aimed to compare the antimicrobial resistance patterns and DNA restriction patterns by... more This study aimed to compare the antimicrobial resistance patterns and DNA restriction patterns by Pulsed-Field Gel Electrophoresis (PFGE) between Salmonella spp. isolated from broilers and pigs in Thailand and China. One hundred and sixty six isolates were collected from broilers and pigs at slaughterhouses in Khon Kaen, Thailand (n=106) between February to August 2017 and in Chongqing, China (n=60) between March to October 2015. Antimicrobial susceptibility of the isolates was determined using the disk diffusion method with nine antimicrobial agents. Genotypic diversity of the isolates used PFGE of Xbal-digested chromosomal DNA to determine. Of 166 Salmonella isolates, 37 serotypes were identified. The Thai isolates were composed of 18 serotypes, of which S. Rissen was most common (34%). The Chinese isolates consisted of 23 serotypes, of which S. Derby was most common (22%). The antimicrobial resistance profiles of Salmonella isolates demonstrated that 38% (63/166) of the isolates were multidrug resistance (MDR), with 20.8% (22/106) of the Thai isolates and 68.3% (41/60) of the Chinese isolates being identified as MDR. Salmonella Typhimurium and S. Give isolated from Thailand and China were found to be clonally unrelated. It is noteworthy that a close genetic relationship, at more than 90% similarity, was observed between S. Rissen isolated from pigs in China and Thailand. Based on these results, better surveillance systems for Salmonella spp. should be implemented, and the use of antibiotics in food animal production should be more tightly regulated in both Thailand and China. The monitoring program of Salmonella dissemination should stay vigilant for S. Rissen between Thailand and China.
Veterinary Integrative Sciences
Salmonella Enteritidis is one of the most common serovars associated with gastroenteritis in huma... more Salmonella Enteritidis is one of the most common serovars associated with gastroenteritis in humans. Fluoroquinolone resistance in non-typhoidal Salmonella including S. Enteritidis has increased globally and is considered as a threat to public health. In this study, we aimed to investigate the occurrence of ciprofloxacin resistance and plasmid-mediated quinolone resistance (PMQR) genes, and examine virulence gene profiles of 69 S. Enteritidis isolates recovered from 46 boot swab and 23 intestinal samples collected from 69 commercial intensive broiler farms in Thailand. Ciprofloxacin susceptibility of these isolates was determined using microbroth dilution method. PCR was used to detect 5 common PMQR genes (qnrA, qnrB, qnrS, aac(6')-Ib-cr and qepA) and 12 important virulence genes (agfA, invA, spaN, prgH, sitC, ssaQ, mgtC, sopB, sifA, tolC, cdtB and spvC). All S. Enteritidis showed reduced susceptibility to ciprofloxacin, with the MIC values of 0.125-0.50 µg/mL. However, these is...
Veterinary World
Background and Aim: Mastitis is an important disease that can reduce milk production and farmer i... more Background and Aim: Mastitis is an important disease that can reduce milk production and farmer income as well as negatively affect human health. This study aimed to summarize dairy mastitis in Indonesia, both subclinical mastitis (SCM) and clinical mastitis (CM), and its prevalence in different provinces, the diagnostic methods, and the animal species. Materials and Methods: Relevant studies on mastitis in dairy animals in Indonesia were obtained from PubMed, Scopus, ProQuest, Google Scholar, and Garuda. The title and abstract were screened for the eligibility of the studies. The full text of the selected studies was assessed and the data were extracted for analysis. To determine the pooled estimate of the prevalence of mastitis, a random-effects model was performed using the “Meta” and “Metaphor” packages in the R software version 4.2.2. The heterogeneity of several characteristics (mastitis type, provinces, animal species, and diagnostic methods) was evaluated through subgroup me...
International Journal of Infectious Diseases, 2022
Poultry Science, 2021
One hundred and twenty chicken samples from feces (n = 80), the carcass surface at slaughter at 2... more One hundred and twenty chicken samples from feces (n = 80), the carcass surface at slaughter at 2 meat chicken farms (n = 20), and retail chicken meat from 5 markets (n = 20) collected during 2018 and 2019 were examined for the prevalence of plasmid-mediated quinolone resistance (PMQR) in Escherichia coli. We detected qnrS-positive E. coli in a total of 74 samples from feces (n = 59), the carcass surface (n = 7), and retail meat (n = 8). These 74 qnrS-positive isolates were tested for antimicrobial susceptibility to determine the minimum inhibitory concentrations (MICs) of certain antimicrobials and genetically characterized. Ampicillin-resistance accounted for 71 of the 74 isolates (96%), followed by resistance to oxytetracycline (57/74; 77%), enrofloxacin (ERFX) (56/74; 76%), sulfisoxazole (SUL) (56/74; 76%), trimethoprim (TMP) (49/74; 66%), and dihydrostreptomycin (48/74; 65%). All farm-borne SUL- and TMP-resistant isolates except one were obtained from samples from farm A where a combination of sulfadiazine and TMP was administered to the chickens. Concentrations of ERFX at which 50 and 90% of isolates were inhibited were 2 μg/mL and 32 μg/mL, respectively. Diverse pulsed-field gel electrophoresis (PFGE) patterns of XbaI-digested genomic DNA were observed in the qnrS-positive isolates from fecal samples. Several isolates from feces and the carcass surface had identical XbaI-digested PFGE patterns. S1-nuclease PFGE and Southern blot analysis demonstrated that 7 of 11 dfrA13-positive fecal isolates carried both the qnrS and dfrA13 genes on the same plasmid, and 2 of 3 dfrA1-positive isolates similarly carried both qnrS and dfrA1 on the same plasmid, although the PFGE patterns of XbaI-digested genomic DNA of the isolates were different. These results suggest that the qnrS gene is prevalent in chicken farms via horizontal transfer of plasmids and may partly be co-selected under the use of TMP.
Diagnostic Microbiology and Infectious Disease, 2004
We developed and evaluated a single-step, multiplex polymerase chain reaction (PCR) assay for dis... more We developed and evaluated a single-step, multiplex polymerase chain reaction (PCR) assay for distinguishing (1) between the Mycobacterium tuberculosis complex (MTBC) and mycobacteria other than tuberculosis (MOTT) and (2) between M. tuberculosis and M. bovis species. The assay targeted the 16S and the 23S rDNA to distinguish between MTBC and MOTT species, and the oxyR gene to distinguish between M. tuberculosis and M. bovis strains. Clinical samples and reference strains (N = 156) comprised 93 strains of M. tuberculosis, 44 of M. bovis, 1 M. africanum strain, and 18 strains representing 9 different species of MOTTs. MOTTs generated only a single PCR product of about 2.5 kilobase; however, all of the MTBC strains produced a 118 base pair (bp) fragment and an additional 270 bp fragment was obtained for M. tuberculosis and M. africanum when the primer pair oxyRTB-2.1/oxyRMT-1 was used. When oxyRTB-2.1/oxyRMB-1 primers were used, the 270 bp fragment was obtained for only M. bovis. The assay needed as little as 1 pg of purified genomic DNA to make a positive identification.
Veterinary World, Oct 31, 2023
Background and Aims: Methicillin-resistant Staphylococci (MRS) seriously threatens animal and hum... more Background and Aims: Methicillin-resistant Staphylococci (MRS) seriously threatens animal and human health. Repeated antibiotic use allows the bacteria to develop resistance to several antibiotic classes and become multidrug-resistant (MDR). Canine pyoderma, a common skin condition in dogs, is mainly caused by Staphylococci, including MRS. Detecting this infection in all canine populations is crucial to develop a proper preventive plan. This study estimated the prevalence, antibiogram, and risk factors of MRS in canine patients at a referral animal hospital in Khon Kaen, Thailand. Materials and Methods: Skin swabs and relevant information were collected from 56 client-owned dogs that visited the hospital from September 2019 to September 2020. Staphylococci colonies were subjected to molecular identification and antibiotic susceptibility tests using an automated system (VITEK ® 2). These colonies were also genetically identified using multiplex-polymerase chain reaction (PCR) and sequencing. The mecA gene, encoding methicillin resistance, was detected using simplex-PCR. The risk factors of MRS infection and their association with MRS infection were analyzed using logistic regression and the Chi-square test, respectively. Results: The prevalence of MRS was found to be 35.7% (20/56 dogs). By species, methicillin-resistant Staphylococcus pseudintermedius was found in 24 of 104 isolates (23.1%), and all samples were MDR. Receiving systemic antibiotics in the past 6 months was a major risk factor associated with MRS infection (p < 0.05; odds ratio (OR) > 1). In addition to the MRS isolates, the mecA gene was also detected in methicillin-susceptible Staphylococci isolates. This might be because of the high expression of blaI, and mutations in c-di-AMP cyclase DacA, RelA, and Fem proteins. Conclusion: A high prevalence of MRS and MDR was observed in the studied population, which might be potentially due to improper antibiotic use by the owners and horizontal transfer of drug-resistance genes.
Acta Pharmaceutica Sinica B
Veterinary Integrative Sciences
Salmonella is one of the major causes of foodborne diseases in humans. These bacteria can coloniz... more Salmonella is one of the major causes of foodborne diseases in humans. These bacteria can colonize within the gastrointestinal tracts of both humans and animals, and there have been reports of incidences of Salmonella in horses. This study aimed to investigate the prevalence, serotypes, and antimicrobial resistance of Salmonella isolates from racehorses and horsemen, as well as to explore the possible transmission between horses and humans. Fecal samples from racehorses (247 samples) and horsemen (33 samples) were collected from horse farms located in 3 provinces of upper Northeastern Thailand between March and August 2019. Salmonella was isolated and identified. Broth microdilution was used to determine the minimal inhibitory concentrations (MICs) of the antimicrobial agents for antimicrobial. Salmonella isolates were detected in 4.86% (12/247) of racehorses and 3.03% (1/33) of horsemen. The most commonly found serotypes in the isolates obtained from the racehorses were Abony (25%)...
Elemental sulfur has been used for a long time to treat superficial mycoses in both medical and v... more Elemental sulfur has been used for a long time to treat superficial mycoses in both medical and veterinary practices, but effective treatment requires high concentrations of sulfur. Encapsulation of sulfur in nanoparticles can potentially allow the delivery of high concentrations of sulfur to infections. Sulfur nanoparticles were synthesized from Catharanthus roseus extract and sodium sulfide at various pH conditions (4, 6, and 7). Particle identification and characterizations were performed by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), and dynamic light scattering analysis. Broth microdilution and time-kill assays were used to determine the antifungal effect against Microsporum canis DMST29297. The X-RD analysis showed that the fine yellow powder of sulfur nanoparticles contained α-orthorhombic sulfur and SEM showed a uniform distribution and similarity in size of almost spherical particles. Sulfur nanoparticles synthesized with C. roseus extract at pH 7 ...
Veterinary Integrative Sciences, 2021
Carbapenem-resistant Enterobacteriaceae (CRE) have emerged as an urgent threat to public health. ... more Carbapenem-resistant Enterobacteriaceae (CRE) have emerged as an urgent threat to public health. This study aimed to determine the occurrence of CRE and the carbapenemase genes in a farrow-to-finish pig farm, and to investigate carriage proportion and maintenance of CRE during the pig production cycle. We conducted a cross-sectional study by collecting 200 rectal swabs from healthy pigs of 5 groups: gilts, sows, piglets, weaners, and fatteners. In the longitudinal study, 20 healthy pigs were followed from 2 to 26 weeks old, and rectal swabs were collected from each pig for 5 times. Samples were screened for CRE using MacConkey agar supplemented with meropenem at 0.5 µg/mL. Identification and antimicrobial susceptibility pattern of the recovered isolates were determined using an automated system. PCR was used to detect carbapenemase genes. The occurrence of Enterobacteriaceae isolates with the carbapenem resistant phenotype and/or harboring the blaOXA-48 gene was 3% (6/200) in the cr...
Veterinary Integrative Sciences, 2021
This study aimed to determine the prevalence, genotypic diversity, and antimicrobial resistance p... more This study aimed to determine the prevalence, genotypic diversity, and antimicrobial resistance pattern of Salmonella isolated from meat goats in the Northeastern region of Thailand. A total of 1,014 rectal swabs were collected from 30 meat goat farms during April to November, 2018. Salmonella was isolated and identified according to the International Organization for Standardization protocol (ISO-6579:2002/AMD:2017) and serotyped using a slide agglutination test following the Kauffmann-White scheme. An antimicrobial susceptibility test to determine minimal inhibitory concentration (MIC) of 12 antimicrobial agents was performed using a broth microdilution method following the CLSI protocol (2017). Pulsed-field gel electrophoresis (PFGE) of XbaI digested chromosomal DNA was used to determine genotypic diversity of the isolates. The overall prevalence of Salmonella in the meat goats was 1.28%. A total of 13 Salmonella isolates recovered from the meat goats belonged to 4 serovars inclu...
Veterinary Integrative Sciences, 2021
Food-producing animals are the major reservoir for Salmonella infections in humans. Salmonella co... more Food-producing animals are the major reservoir for Salmonella infections in humans. Salmonella contamination and spread of antimicrobial resistance genes can occur during the production chain of animal products. The aims of this study were to investigate antimicrobial resistance patterns and compare the proportions of multidrug resistance and the presence of mobile colistin resistance (mcr) genes, mcr-1, mcr-2 and mcr-3, among Salmonella isolates which were recovered from pork at two different standard practice slaughterhouses and retails during 2014-2017 in Thailand. Salmonella isolates recovered from good standard practice slaughterhouses (GSH, n=75), below standard practice slaughterhouses (BSH, n=75), good standard practice retails (GRT, n=75) and below standard practice retails (BRT, n=75) were examined for their antimicrobial resistance patterns and the existence of mcr-1 to mcr-3 genes. Salmonella strains of the 4 origins showed similar resistance rates to almost all antimicr...
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Papers by Patchara Phuektes