• Fisheries and Aquatic Sciences
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• 제12권1호
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• pp.24-28
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• 2009

A tetracycline resistant Vibrio parahaemolyticus, capable of growing on TCBS medium containing tetracycline, was isolated from cultivated fishes. A gene responsible for the tetracycline resistance was cloned from chromosomal DNA of the V. parahaemolyticus strain using Escherichia coli KAM3, which lacks major multi-drug efflux pumps (${\Delta}acrB$) as host cells. The nucleotide sequence and homology analysis revealed an open reading frame (ORF) for tetracycline resistance protein (TetB). In order to characterize the antibiotic resistance of TetB originated from the V. parahaemolyticus strain, the gene was sub cloned into plasmid pSTV28. The resulting plasmid was designated as pSTVTetB and transformated into E. coli KAM3. E. coli KAM3 cells harboring the recombinant plasmid pSTVTetB are able to grow on plates containing tetracycline and oxytetracycline but not doxycycline, indicating that the tetB gene confers the tetracycline- and oxytetracycline-resistance to the host cell.

• 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.

• Fisheries and Aquatic Sciences
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• 제9권2호
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• pp.97-100
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• 2006

To determine whether the tetracycline resistance genes tet (34), tet (M), and tet (S) can be transferred among bacteria, we used a filter mating experiment allowing intimate cell-cell contact between donor and recipient. The tet(34) gene, conveyed on a chromosome of Vibrio species (No. 6 and SW-42) was not transferred to Escherichia coli JM109, suggesting that it is not transferred among bacterial species. The tet (M) gene was transferred from three Vibrio strains (4-E, SW-18, and SW-38) to E. coli at frequencies of $8.5{\times}10^{-5}\;to\;2.1{\times}10^{-6}$. The tet(S) gene was transferred from Lactococcus garvieae KHS98032 to E. coli at a frequency of $1.8{\times}10^{-6}$. Transconjugated recipients showed increased minimum inhibitory concentrations against oxytetracycline. Although the donors possess the Tn916-Tn1545 transposons, they were not detected in transformed recipients, suggesting that the transfer of tet(M) and tet(S) is mediated by elements or mechanisms. Two ribosomal protect protein genes were also transmissible from marine bacteria to E. coli, suggesting gene hopping among marine, terrestrial, and human environments.

• Asian Pacific Journal of Cancer Prevention
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• 제15권20호
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• pp.8883-8886
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• 2014

Background: Tetracycline is an antibiotic widely used for the treatment of Helicobacter pylori infection, but its effectiveness is decreasing due to increasing bacterial resistance. The aim of this study was to investigate the occurrence of 16S rRNA mutations associated with resistance or reduced susceptibility to tetracycline ofHelicobacter pylori by real-time PCR (RT-PCR) assays from culture. Materials and Methods: Tetracycline susceptibility and minimal inhibition concentration (MIC) was determined by the Epsilometer test (Etest) method. A LightCycler assay developed to detect these mutations was applied to DNA extracted from culture. The 16S rRNA of these isolates was sequenced and resistance-associated mutations were identified. From 104 isolates of H. pylori examined, 11 showed resistance to tetracycline. Results: LightCycler assay was applied to DNA extracted from 11 tetracycline-susceptible and 11 tetracycline resistance H. pylori isolates. In our study the sequencing of the H. pylori wild types in 16 s rRNA gene were AGA 926-928 with MIC (0.016 to $0.5{\mu}g/ml$), while the sequencing and MIC for resistant were GGA and AGC, (0.75 to $1.5{\mu}g/ml$), respectively. Also we found a novel mutation in 2 strains with $84^{\circ}C$ as their melting temperatures and exhibition of an A939C mutation. Conclusions: We conclude that real-time PCR is an excellent method for determination of H. pylori tetracycline resistance related mutations that could be used directly on biopsy specimens.

• 생명과학회지
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• 제15권6호
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• pp.863-870
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• 2005

2002년 2월부터 2005년 4월까지 호흡기질환 환자로부터 분리된 M. pneumeniae 123 균주의 tetracycline과 erythromycin에 대한 MIC 범위는 각각 $0.5\~1.0$, and $0.5\~512{\mu}/ml$ 이었다. 분리된 M. pneumoniae 123 균주에서 plasmid DNA는 확인되지 않았다. 분리된 M. pneumoniae 123 균주 중에서 57($46.3\%$) 균주가 tetracycline에 저항성인 tetM유전자를 가지고 있었으며, 235 rRNA domain V에 erythromycin에 저항성 변이를 일으킨 균주가 60($48.8\%$)이었다. erythromycin에 저항성 변이를 일으키지 않은 63균주 중에서 tetM 유전자를 가지고 있는 균주는 36($57.1\%$)이었으며, erythromycin에 저항성 변이를 일으킨 60균주 중에서 21($35.0\%$ 균주가 tetM 유전자를 가지고 있었다. 본 연구로써 국내에서 tetracycline과 erythromycin에 대한 저항성 M. pneumoniae 균주의 분리율이 외국에 비하여 높으며, M. pneumoniae 감염의 치료에 erythromycin이 일차 선택제가 될 수 없으므로 이에 대한 범국가적 조사가 필요하다고 생각된다.

• 한국수산과학회지
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• 제56권4호
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• pp.388-400
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• 2023

Aeromonas spp. and Pseudomonas spp. are opportunistic pathogens widely distributed in the aquatic environment. To test the antibiotic susceptibility, the MIC of the 18 antibiotics mainly used in aquaculture were measured. Aeromonas spp. and Pseudomonas spp. straoms had different resistance patterns against most antibiotics. The MIC of tetracycline for four Aeromonas spp. strains (10.5%) was < 0.25 ㎍/mL. However, 0.5-4 ㎍/mL tetracycline inhibited most Pseudomonas spp. strains. The tet resistance performance of 14 genes including tet(B), tet(E), and tet(M) were investigated. Investigating, the tetracycline resistance gene of 38 Aeromonas spp. strains detected tet(A) in 21 strains (55.3%). Two Pseudomonas spp. strains showed high MIC values and no inhibition zone. tet gene analysis detected tet(D) in only one strain (5%).

• 한국동물위생학회지
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• 제32권3호
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• pp.227-239
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• 2009

At the present study, it was aimed to detect virulence genes and antimicrobial resistance genes among 102 strains of 12 Salmonella serotypes isolated from pigs and cattle. In polymerase chain reaction (PCR), invA was detected from all strains of Salmonella spp., spvC was detected from Salmonella enterica serotype Enteritidis (S. Enteritidis) (100%), S. Bradenburg (75%), and S. Typhimurium (20.4%). Drug resistance related genes of 12 types were detected from all strains. TEM ($bla_{TEM}$) gene was detected from 51 (92.7%) of 55 $\beta$-lactams (54 ampicillin or 1 amoxicillin) resistance strains. 55 (100%) of 55 chloramphenicol resistance strains, 3 (100%) of 3 gentamicin resistance strains and 5 (100%) of 5 kanamycin resistance strains did contain cml, aadB, and aphA1-Iab, respectively. strB (89.9%), strA (88.4%), aadA2 (84.1%) and aadA1 (72.5%) were detected from 69 streptomycin resistance strains. sulII and dhfrXII were detected from 49 (100%) of 49 sulfamethoxazole/trimethoprim resistance strains, but sulI was not detected. tetA (97.9%) and tetB (21.6%) were detected from 97 tetracycline resistance strains. int gene was detected from 58 (56.9%) of 102 strains. 54 S. Typhimurium of 102 Salmonella spp. were attempted to detect drug resistance genes. TEM was detected from 44 (95.7%) of 46 $\beta$-lactams (45 ampicillin or 1 amoxicillin) resistance strains. cmlA was detected from 51 (100%) of 51 chloramphenicol resistance strains. aadA2 (100%), strA (100%), strB (100%), and aadA1 (79.6%) were detected from 54 streptomycin resistance strains. sulII (100%) and dhfrXII (100%) were detected from 49 sulfamethoxazole/trimethoprim resistance strains. tetA was detected from 54 (100%) of 54 tetracycline resistance strains. int gene was detected from 54 (100%) of 54 strains. The major drug resistance pattern and resistance gene profile were ampicillin, chloramphenicol, streptomycin, sulfamethoxazole/trimethoprim and tetracycline (ACSSuT) and TEM, cmlA, aadA1, aadA2, strA, strB, sulII, dhfrXII, tetA and int, respectively.

• 한국동물위생학회지
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• 제36권2호
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• pp.73-78
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• 2013

This study was conducted to investigate antibiotic resistance among Salmonella Typhimurium isolates from diseased pigs in Gyeongbuk province during the period 1998~2011. One hundred forty one isolates were tested for antibiotic resistance using the standard disk diffusion method and were examined for presence of resistance gene by PCR method. S. Typhimurium showed high drug resistance rates to tetracycline (95.7%), streptomycin (93.6%), ampicillin (86.5%), cephalothin (80.1%), gentamicin (79.4%), and trimethoprim/sulfamethoxazole (72.3%). Resistance gene, blaTEM, blaPSE1, tetA, tetB, tetG, sul1, sul2, aadA, strA, grm, and temA were detected among the antibiotic resistance isolates and temB, tetC, aadB gene were not detected. One hundred twenty one (89.6%) tetA, two (1.5%) tetB and one (0.7%) tetG gene were detected in the 135 tetracycline resistant isolates. Two (1.6%) temA gene were detected in one hundred twenty two ampicillin resistance isolates and temB was not detected.

• 미생물학회지
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• 제46권4호
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• pp.326-333
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• 2010

2003년부터 2009년까지 서울지역 소아에서 분리된 nontyphoid Salmonella 105주에 대해서 혈청형, 항생제 내성양상, integron의 특징과 PFGE를 수행하였다. 혈청형은 총 18종으로 S.Enteritidis가 가장 많이 분리되었고, 그 다음은 Montevide였다. 항균제 내성은 혈청형별로 차이가 있었으나 전체 살모넬라에 대해서 10종의 항균제에 대한 내성률은 ampicillin이 60%로 가장 높았으며, tetracycline 46.7%, streptomycin 35.2%, nalidixic acid 28.6% 순이었다. 다재내성 유형을 알아본 결과 nalidixic acid 단독 내성이 15.7%로 가장 많았고, ampicillinampicillin/sulbactam-tetracycline형이 14.5%, ampicillin-streptomycin-chloramphenicol-tetracycline형이 10.8%였다. Integron에 대한 연구 결과 integron 보유율은 19%로 20주에서 class 1 integron을 가지고 있었고 gene cassette는 20%만 확인이 되었다. 확인된 gene cassette는 aadA2, blaP1과 dfrA12-aadA2, dfr17-aadA5, aadA7이였다. 연도별 분리균의 유연관계를 확인 하고자 가장 분리율이 높은 S. Enteritidis 50주에 대해서 PFGE를 수행한 결과 3가지 Pulsotype으로 나눠어졌다. 3주를 제외한 모든 균주는 similarity 89.8%의 비교적 유연관계가 높은 균임을 확인할 수 있었다.

• Journal of Microbiology
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• 제45권5호
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• pp.379-387
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• 2007

A hundred and seventeen antibiotic-resistant Escherichia coli strains were isolated from public tap and spring waters which were polluted by fecal coliforms. There were no significant differences between two water sources as to the coliform pollution level (p> 0.05). All E. coli isolates were detected to be resistant to one or more antibiotics tested. Nearly 42% of the isolates showed multiresistant phenotype. Three (2.5%) of these isolates contained class 1 integron. Sequencing analysis of variable regions of the class 1 integrons showed two gene cassette arrays, dfr1-aadA1 and dhfrA17-aadA5. Resistance to ampicillin, tetracycline or trimethoprim-sulfamethoxazole was transferable according to the results of conjugation experiments. The rate of tetracycline resistance was 15%. tet(A)-mediated tetracycline resistance was widespread among tetracycline-resistant E. coli isolates. Genotyping by BOX-polymerase chain reaction (BOX-PCR) showed that some of the strains were epidemiologically related. This is the first report on the prevalence and characterization of class 1 integron-containing E. coli isolates of environmental origin in Turkey.