• 대한수의학회지
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• 제61권3호
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• pp.26.1-26.8
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• 2021

Acinetobacter is a bacteria found in the environment and clinical specimens, causing nosocomial infection and antimicrobial resistance (AMR) threats. This study examined the prevalence, species, and AMR characteristics of Acinetobacter isolated from surgical practice and the laboratory dog husbandry room environments (n = 235) at Rajamangala University of Technology Tawan-ok veterinary hospital during 2018-2019. The prevalence of Acinetobacter in the laboratory dog husbandry room and veterinary belongings were 2.55% and 0.43%, respectively. Species determination was Acinetobacter hemolyticus (2.13%) and Acinetobacter baumannii (0.43%) from environments in the laboratory dog husbandry room, and Acinetobacter junii (0.43%) from the shoes used in the surgical practice room. AMR was observed in both study environments and the specimens sent to the Veterinary Diagnostic Center. These isolates had a high resistant percentage to amoxicillin-clavulanic acid (84.62%), sulfamethoxazole-trimethoprim (61.54%), and cephalexin (53.85%) but were susceptible to imipenem. Compared to the isolates recovered from the clinical specimens, most isolates derived from environments exhibited multidrug resistance and shared correlated resistance patterns. These results highlight the need for sanitization in the dog husbandry room. Furthermore, the AMR results can be used as a preliminary baseline for studying AMR Acinetobacter contamination in animals and their environments.

• 한국동물위생학회지
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• 제32권4호
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• pp.325-334
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• 2009

Salmonella spp. are the important pathogens both economically and clinically in animals as well as human. Some of them have highly zoonotic potentials even though they are asymptomatic in animals. Therefore, the prevalence of Salmonella spp. in animals is highly concerned for human health. The present study was carried out to investigate the prevalence, antimicrobial resistance and PFGE patterns of Salmonella spp. isolated from chickens at slaughterhouse in Incheon area. The overall isolation rate of Salmonella spp. from cloaca and cecum specimens was 7.3 % (37/510). Thirty seven isolates of Salmonella spp. were identified to 5 serotypes; S. Enteritidis, S. Newport, S. Typhimurium, S. Gallinarum, and S. Derby with prevalence of 46.0%, 40.5%, 8.1%, 2.7%, and 2.7%, respectively. Resistance to nalidixic acid was found in 97.3% of Salmonella spp. isolated, followed by streptomycin (16.2%), tetracycline (16.2%), ampicillin (5.4%). Only 6 isolates (16.2%) showed resistance to more than two antimicrobials. In PFGE analysis of chicken and human isolates with Xba I, S. Enteritidis isolates from chicken showed very high similarity over 82.8% and also the similarity was very high in the comparison with human isolates. However, the higher similarity (100%) was observed among chicken isolates of S. Typhimurium. These results suggest the close genetic relatedness of Salmonella spp. isolated from chickens with human.

• 한국동물위생학회지
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• 제33권1호
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• pp.51-57
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• 2010

Salmonella Typhimurium is a virulent pathogen for human and animal. We studied serotypes, biochemical characteristics, and antimicrobial resistance of S. Typhimurium isolated from diseased pigs in Gyeongbuk province over 1998 to 2008. One hundred sixteen isolates were identified as S. Typhimurium by biochemical characteristics and serotypes from 90 farms. The biochemical characteristics of S. Typhimurium isolates was production of $H_2S$, indole-negative, fermentation of mannitol, dulcitol, sorbitol, inositol, rhamnose, and maltose, and ornithine decarboxylase. At antimicrobial susceptibility test, the majority of isolates were highly susceptible to amoxicillin/clavulanic acid, cefepime, ciprofloxacin, while were highly resistant streptomycin, cephalothin, enrofloxacin, nalidixic acid, apramycin, chloramphenicol, tetracycline. The isolates were divided into 65 resistant patterns and 47 of the isolates were shown as a DT104 ASSSuT resistant phenotype.

• Journal of Microbiology and Biotechnology
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• 제32권12호
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• pp.1537-1546
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• 2022

Staphylococcus aureus is a cause of high mortality in humans and therefore it is necessary to prevent its transmission and reduce infections. Our goals in this research were to investigate the frequency of methicillin-resistant S. aureus (MRSA) in Taif, Saudi Arabia, and assess the relationship between the phenotypic antimicrobial sensitivity patterns and the genes responsible for resistance. In addition, we examined the antimicrobial efficiency and application of silver nanoparticles (AgNPs) against MRSA isolates. Seventy-two nasal swabs were taken from patients; MRSA was cultivated on Mannitol Salt Agar supplemented with methicillin, and 16S rRNA sequencing was conducted in addition to morphological and biochemical identification. Specific resistance genes such as ermAC, aacA-aphD, tetKM, vatABC and mecA were PCR-amplified and resistance plasmids were also investigated. The MRSA incidence was ~49 % among the 72 S. aureus isolates and all MRSA strains were resistant to oxacillin, penicillin, and cefoxitin. However, vancomycin, linezolid, teicoplanin, mupirocin, and rifampicin were effective against 100% of MRSA strains. About 61% of MRSA strains exhibited multidrug resistance and were resistant to 3-12 antimicrobial medications (MDR). Methicillin resistance gene mecA was presented in all MDR-MRSA strains. Most MDR-MRSA contained a plasmid of > 10 kb. To overcome bacterial resistance, AgNPs were applied and displayed high antimicrobial activity and synergistic effect with penicillin. Our findings may help establish programs to control bacterial spread in communities as AgNPs appeared to exert a synergistic effect with penicillin to control bacterial resistance.

• 한국미생물·생명공학회지
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• 제48권2호
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• pp.230-235
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• 2020

The global evolution of antibiotic resistance has threatened the efficacy of available treatment options with ravaging impacts observed in developing countries. As a result, investigations into the prevalence of antibiotic resistance and the role of plasmids are crucial. In this study, we investigated the presence and distribution of bla_TEM and gyrA genes, plasmid profiles, and the antimicrobial susceptibility pattern of Salmonella strains isolated from raw meat and stool sources across Niger State, Nigeria. Ninety-eight samples, comprising 72 raw meat and 26 stool samples, were screened for Salmonella spp. The antimicrobial susceptibility of Salmonella isolates to 10 commonly used antimicrobial agents was determined using the KirbyBauer disc diffusion method. Isolates were further analyzed for plasmids, in addition to PCR amplification of beta-lactamase (bla_TEM) and gyrA genes. A total of 31 Salmonella spp. were isolated, with 22 from raw meat (70.97%) and 9 from stool (29.03%). Salmonella spp. with multiple resistance patterns to ceftazidime, cefuroxime, ceftriaxone, erythromycin, ampicillin, cloxacillin, and gentamicin were detected. Ofloxacin and ciprofloxacin were found to be the most effective among the antibiotics tested, with 67.7% and 93.5% susceptible isolates, respectively. Nine (29.03%) isolates harbored plasmids with molecular sizes ranging between 6557 bp and 23137 bp. PCR amplification of gyrA was detected in 1 (3.23%) of the 31 isolates while 28 isolates (90.32%) were positive for bla_TEM. This study shows the incidence of antibiotic resistance in Salmonella isolates and the possible role of plasmids; it also highlights the prevalence of ampicillin resistance in this local population.

• 한국수산과학회지
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• 제55권5호
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• pp.505-513
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• 2022

In this study, 143 strains of Enterococcus spp. were isolated from inland pollution sources near shellfish farms on the west coast of South Korea. Not all isolated Enterococcus spp. strains possessed vancomycin resistance genes (VanA and VanB). However, since vancomycin-resistance Enterococcus (VRE) have been detected not only in the clinical field but also out in the world, it is possible that the VRE gene may be transferred to other bacterial strains commonly found in coastal waters where seafood is produced. It is important to monitor trends in the appearance of VRE. In addition, antimicrobial resistance patterns of isolates were examined in this study. Overall antimicrobial resistance rates were high: ciprofloxacin (32.2% of isolates resistant), chloramphenicol (30.8%), quinupristin/dalfopristin (19.6%), and tylosin (15.4%). Eight E. faecium strains (6.2%), out of the 129 strains assessed, showed multidrug resistance. All multidrug-resistant E. faecium showed resistance to erythromycin, quinupristin/dalfopristin, tetracycline, and tylosin, in all 14 strains. All multidrug-resistant E. faecalis showed resistance to erythromycin, quinupristin/dalfopristin, tetracycline, and tylosin. Both multidrug-resistant E. faecium and multidrug-resistant E. faecalis showed common resistance to erythromycin, quinupristin/dalfopristin, tetracycline, and tylosin.

• Journal of Veterinary Science
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• 제24권6호
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• pp.82.1-82.12
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• 2023

Background: The current conventional serotyping based on antigen-antisera agglutination could not provide a better understanding of the potential pathogenicity of Salmonella enterica subsp. enterica serovar Brancaster. Surveillance data from Malaysian poultry farms indicated an increase in its presence over the years. Objective: This study aims to investigate the virulence determinants and antimicrobial resistance in S. Brancaster isolated from chickens in Malaysia. Methods: One hundred strains of archived S. Brancaster isolated from chicken cloacal swabs and raw chicken meat from 2017 to 2022 were studied. Two sets of multiplex polymerase chain reaction (PCR) were conducted to identify eight virulence genes associated with pathogenicity in Salmonella (invasion protein gene [invA], Salmonella invasion protein gene [sipB], Salmonella-induced filament gene [sifA], cytolethal-distending toxin B gene [cdtB], Salmonella iron transporter gene [sitC], Salmonella pathogenicity islands gene [spiA], Salmonella plasmid virulence gene [spvB], and inositol phosphate phosphatase gene [sopB]). Antimicrobial susceptibility assessment was conducted by disc diffusion method on nine selected antibiotics for the S. Brancaster isolates. S. Brancaster, with the phenotypic ACSSuT-resistance pattern (ampicillin, chloramphenicol, streptomycin, sulphonamides, and tetracycline), was subjected to PCR to detect the corresponding resistance gene(s). Results: Virulence genes detected in S. Brancaster in this study were invA, sitC, spiA, sipB, sopB, sifA, cdtB, and spvB. A total of 36 antibiogram patterns of S. Brancaster with a high level of multidrug resistance were observed, with ampicillin exhibiting the highest resistance. Over a third of the isolates displayed ACSSuT-resistance, and seven resistance genes (β-lactamase temoneira [bla_TEM], florfenicol/chloramphenicol resistance gene [floR], streptomycin resistance gene [strA], aminoglycoside nucleotidyltransferase gene [ant(3")-Ia], sulfonamides resistance gene [sul-1, sul-2], and tetracycline resistance gene [tetA]) were detected. Conclusion: Multidrug-resistant S. Brancaster from chickens harbored an array of virulence-associated genes similar to other clinically significant and invasive non-typhoidal Salmonella serovars, placing it as another significant foodborne zoonosis.

• 한국수산과학회지
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• 제52권6호
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• pp.605-616
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• 2019

This study evaluated the abundance and antimicrobial resistance of Escherichia coli in oysters Crassostrea gigas and major inland pollution sources sampled in 2014-2015 from Jaranman-Saryangdo on the southern coast of Korea. The ranges of the geometric mean of E. coli concentrations in oysters and major inland pollution sources were <20-29.8 MPN/100 g and 7.5-137.2 MPN/100 g, respectively. We isolated 247 strains of E. coli (28 from oysters and 247 from major inland pollution sources) and examined the antimicrobial resistance patterns of all isolates. Isolates from both sources were highly resistant to rifampin (99.5-100%) and cephalothin (70.8-78.6%). The resistance rate was higher in E. coli isolated from oysters those from inland pollution sources. Multiple resistance against at least four antimicrobials was observed in 85.7% and 21.0% of the oyster and major inland pollution sources isolates, respectively.

• 한국수산과학회지
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• 제42권4호
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• pp.322-328
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• 2009

Three-hundred and sixteen Escherichia coli strains from seawater, and a variety of farmed fishes, including oliver flounder (Paralichthys olivaceus), black rock fish (Sebastes schlegeli), red sea bream (Pagrus major) and sea bass (Lateolabrax japonicus) between May to October in 2004, were tested by agar dilution method to determine their susceptibility patterns to 17 antimicrobial agents. Overall, 92.1% of Escherichia coli isolates from samples showed antimicrobial resistance to at least one antimicrobial agent and the multiple resistance was seen in 173 isolates (54.7%). The resistance of E. coli isolates to tetracycline (74.1%) was highest, followed by cephalothin (69.9%), doxycycline (66.5%), streptomycin (47.2%), ampicillin (46.2%), cefazolin (31.6%), enrofloxacin (31.0%). norfloxacin (28.2%). The most frequent resistance pattern was TE-D-CF-CIP-ENO-NOR-AM-S-C-SXT-AmC-CZ (14.7%), followed by CF (6.2%), TE (5.1%), TE-CF (4.5%) in 177 isolates from fishes and TE-D-CF (7.2%) followed by TE-D-CF-S (5.8%), CF and TE-D-S (3.6%) in 139 isolates from seawater.

• 생명과학회지
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• 제18권1호
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• pp.69-74
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• 2008

국내에서 사육중인 말에서 채취한 시료로부터 Stapylococcus aureus를 분리 동정한 결과 39.2%(58/148)의 분리율을 나타내었다. S. aureus의 혈장응고효소 생산능 시험에서는 98.3%가 양성반응을 나타내었고 신선 혈장의 희석농도는 1:2에서 가장 높은 양성반응을 나타내었다. 본 연구에서 최종 동정된 S. aureus의 기본적인 생화학 성상은 일반적으로 알려져 있는 S. aureus의 특성과 유사한 결과를 얻을 수 있었으나, urease test의 경우 전체 균주의 73% 만이 양성 결과를 나타내어 균주별로 다양한 반응 양상을 관찰 할 수 있었다. 또한 34종의 substrate에 대한 분해 양상에 대한 검사 결과 fructose, maltose, ${\alpha}$-hydroxy butyric acid, thymidine-5'-mono phosphate, uridine-5'-mono phosphate 등의 substrate에 대해서는 모든 균주가 이용능력을 가지고 있었지만 ribose, sorbitol, xylose, xylitol 등의 substrate에 대해서는 모든 균주가 기질 이용능력을 가지고 있지 않는 것으로 확인되었다. 그리고 PCR에 의한 S. aureus를 동정한 결과 108bp 크기의 band를 확인하였다. 국내 말에서 분리한 58주의 S. aureus에 대한 약제 내성 양상을 조사한 결과 spectinomycin, sulfonamides, erythromycin, tetracyclin, ciprofloxacin, neomycin, enofloxacin, penicillin 등의 약제에 높은 저항성을 나타내었다.