# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 5387 | 0 | 0.9938 | Assessment of antibiotic susceptibility within lactic acid bacteria strains isolated from wine. Susceptibility to 12 antibiotics was tested in 75 unrelated lactic acid bacteria strains of wine origin of the following species: 38 Lactobacillus plantarum, 3 Lactobacillus hilgardii, 2 Lactobacillus paracasei, 1 Lactobacillus sp, 21 Oenococcus oeni, 4 Pediococcus pentosaceus, 2 Pediococcus parvulus, 1 Pediococcus acidilactici, and 3 Leuconostoc mesenteroides. The Minimal Inhibitory Concentrations of the different antibiotics that inhibited 50% of the strains of the Lactobacillus, Leuconostoc and Pediococcus genera were, respectively, the following ones: penicillin (2, < or =0.5, and < or =0.5 microg/ml), erythromycin (< or =0.5 microg/ml), chloramphenicol (4 microg/ml), ciprofloxacin (64, 8, and 128 microg/ml), vancomycin (> or =128 microg/ml), tetracycline (8, 2, and 8 microg/ml), streptomycin (256, 32, and 512 microg/ml), gentamicin (64, 4, and 128 microg/ml), kanamycin (256, 64, and 512 microg/ml), sulfamethoxazole (> or =1024 microg/ml), and trimethoprim (16 microg/ml). All 21 O. oeni showed susceptibility to erythromycin, tetracycline, rifampicin and chloramphenicol, and exhibited resistance to aminoglycosides, vancomycin, sulfamethoxazole and trimethoprim, that could represent intrinsic resistance. Differences were observed among the O. oeni strains with respect to penicillin or ciprofloxacin susceptibility. Antibiotic resistance genes were studied by PCR and sequencing, and the following genes were detected: erm(B) (one P. acidilactici), tet(M) (one L. plantarum), tet(L) (one P. parvulus), aac(6')-aph(2") (four L. plantarum, one P. parvulus, one P. pentosaceus and two O. oeni), ant(6) (one L. plantarum, and two P. parvulus), and aph(3')-IIIa (one L. plantarum and one O. oeni). This is the first time, to our knowledge, that ant(6), aph(3')-IIIa and tet(L) genes are found in Lactobacillus and Pediococcus strains and antimicrobial resistance genes are reported in O. oeni strains. | 2006 | 16876896 |
| 1324 | 1 | 0.9930 | Molecular characterization of antimicrobial resistance in enterococci and Escherichia coli isolates from European wild rabbit (Oryctolagus cuniculus). A total of 44 Escherichia coli and 64 enterococci recovered from 77 intestinal samples of wild European rabbits in Portugal were analyzed for resistance to antimicrobial agents. Resistance in E. coli isolates was observed for ampicillin, tetracycline, sulfamethoxazole/trimethoprim, streptomycin, gentamicin, tobramycin, nalidixic acid, ciprofloxacin and chloramphenicol. None of the E. coli isolates produced extended-spectrum beta-lactamases (ESBLs). The bla(TEM), aadA, aac(3)-II, tet(A) and/or tet(B), and the catA genes were demonstrated in all ampicillin, streptomycin, gentamicin, tetracycline, and chloramphenicol-resistant isolates respectively, and the sul1 and/or sul2 and/or sul3 genes in 4 of 5 sulfamethoxazole/trimethoprim resistant isolates. Of the enterococcal isolates, Enterococcus faecalis was the most prevalent detected species (39 isolates), followed by E. faecium (21 isolates) and E. hirae (4 isolates). More than one-fourth (29.7%) of the isolates were resistant to tetracycline; 20.3% were resistant to erythromycin, 14.1% were resistant to ciprofloxacin and 10.9% were resistant to high-level-kanamycin. Lower level of resistance (<10%) was detected for ampicillin, quinupristin/dalfopristin and high-level-gentamicin, -streptomycin. No vancomycin-resistance was detected in the enterococci isolates. Resistance genes detected included aac(6')-aph(2''), ant(6)-Ia, tet(M) and/or tet(L) in all gentamicin, streptomycin and tetracycline-resistant isolates respectively. The aph(3')-IIIa gene was detected in 6 of 7 kanamycin-resistant isolates, the erm(B) gene in 11 of 13 erythromycin-resistant isolates and the vat(D) gene in the quinupristin/dalfopristin-resistant E. faecium isolate. This survey showed that faecal bacteria such as E. coli and enterococci of wild rabbits could be a reservoir of antimicrobial resistance genes. | 2010 | 20624632 |
| 5386 | 2 | 0.9930 | Antibiotic resistance of lactic acid bacteria isolated from Chinese yogurts. The aim of this study was to evaluate the susceptibility of 43 strains of lactic acid bacteria, isolated from Chinese yogurts made in different geographical areas, to 11 antibiotics (ampicillin, penicillin G, roxithromycin, chloramphenicol, tetracycline, chlortetracycline, lincomycin, kanamycin, streptomycin, neomycin, and gentamycin). The 43 isolates (18 Lactobacillus bulgaricus and 25 Streptococcus thermophilus) were identified at species level and were typed by random amplified polymorphic DNA analysis. Thirty-five genotypically different strains were detected and their antimicrobial resistance to 11 antibiotics was determined using the agar dilution method. Widespread resistance to ampicillin, chloramphenicol, chlortetracycline, tetracyclines, lincomycin, streptomycin, neomycin, and gentamycin was found among the 35 strains tested. All of the Strep. thermophilus strains tested were susceptible to penicillin G and roxithromycin, whereas 23.5 and 64.7% of Lb. bulgaricus strains, respectively, were resistant. All of the Strep. thermophilus and Lb. bulgaricus strains were found to be resistant to kanamycin. The presence of the corresponding resistance genes in the resistant isolates was investigated through PCR, with the following genes detected: tet(M) in 1 Lb. bulgaricus and 2 Strep. thermophilus isolates, ant(6) in 2 Lb. bulgaricus and 2 Strep. thermophilus isolates, and aph(3')-IIIa in 5 Lb. bulgaricus and 2 Strep. thermophilus isolates. The main threat associated with these bacteria is that they may transfer resistance genes to pathogenic bacteria, which has been a major cause of concern to human and animal health. To our knowledge, the aph(3')-IIIa and ant(6) genes were found in Lb. bulgaricus and Strep. thermophilus for the first time. Further investigations are required to analyze whether the genes identified in Lb. bulgaricus and Strep. thermophilus isolates might be horizontally transferred to other species. | 2012 | 22916881 |
| 1322 | 3 | 0.9930 | Phenotypic and genotypic characterization of antimicrobial resistance in faecal enterococci from wild boars (Sus scrofa). The objective was to study the prevalence of antimicrobial resistance and the mechanisms implicated in faecal enterococci of wild boars in Portugal. One hundred and thirty-four enterococci (67 E. faecium, 54 E. hirae, 2 E. faecalis, 2 E. durans and 9 Enterococcus spp.) were recovered from 67 wild boars (two isolates/sample), and were further analysed. High percentages of resistance were detected for erythromycin, tetracycline, and ciprofloxacin (48.5%, 44.8%, and 17.9%, respectively), and lower values were observed for high-level-kanamycin, -streptomycin, chloramphenicol, and ampicillin resistance (9%, 6.7%, 4.5%, and 3.7%, respectively). No isolates showed vancomycin or high-level-gentamicin resistance. The erm(B), tet(M), aph(3')-IIIa, and ant(6)-I genes were demonstrated in all erythromycin-, tetracycline-, kanamycin-, and streptomycin-resistant isolates, respectively. Specific genes of Tn916/Tn1545 and Tn5397 transposons were detected in 78% and 47% of our tet(M)-positive enterococci, respectively. The tet(S) and tet(K) genes were detected in one isolate of E. faecium and E. hirae, respectively. Three E. faecium isolates showed quinupristin-dalfopristin resistance and the vat(E) gene was found in all of them showing the erm(B)-vat(E) linkage. Four E. faecium isolates showed ampicillin-resistance and all of them presented seven amino acid substitutions in PBP5 protein (461Q-->K, 470H-->Q, 485M-->A, 496N-->K, 499A-->T, 525E-->D, and 629E-->V), in relation with the reference one; a serine insertion at 466' position was found in three of the isolates. Faecal enterococci from wild boars harbour a variety of antimicrobial resistance mechanisms and could be a reservoir of antimicrobial resistance genes and resistant bacteria that could eventually be transmitted to other animals or even to humans. | 2007 | 17658226 |
| 1381 | 4 | 0.9927 | Differences in antimicrobial resistance-related genes of Trueperella pyogenes between isolates detected from cattle and pigs. We investigated antimicrobial resistance-related genes in 109 isolates of Trueperella pyogenes that were isolated in cattle and pigs. All 89 tetracycline-resistant T. pyogenes isolates carried the resistance gene harbored either tetW, tetM, tetA(33), tetK, or tetL. The ermX or ermB were detected in 18 of 23 erythromycin-resistant isolates. Streptomycin-resistant aadA1, aadA9, aadA11, aadA24, strA, or strB were detected in 25 of 83 isolates. There were significant differences in the percentages of tetA(33), ermB, aadA1, aadA9, aadA11, or aadA24 carriage between cattle and pig isolates. In addition, the Class 1 gene cassette was detected only in 17 cattle isolates. This suggests that T. pyogenes isolates acquire resistance gene in each environment of cattle and pigs, and that the transmission of the bacteria between cattle and pigs is limited. | 2024 | 39293943 |
| 1379 | 5 | 0.9927 | Antibiotic Resistance and Genetic Profiles of Vibrio parahaemolyticus Isolated from Farmed Pacific White Shrimp (Litopenaeus vannamei) in Ningde Regions. To better understand the antibiotic resistance, virulence genes, and some related drug-resistance genes of Vibrio parahaemolyticus in farmed pacific white shrimp (Litopenaeus vannamei) in Ningde regions, Fujian province, we collected and isolated a total of 102 strains of V. parahaemolyticus from farmed pacific white shrimp in three different areas of Ningde in 2022. The Kirby-Bauer disk method was used to detect V. parahaemolyticus resistance to 22 antibiotics, and resistant genes (such as quinolones (qnrVC136, qnrVC457, qnrA), tetracyclines (tet A, tetM, tetB), sulfonamides (sulI, sulII, sulIII), aminoglycosides (strA, strB), phenicols (cat, optrA, floR, cfr), β-lactams (carB), and macrolides (erm)) were detected by using PCR. The findings in this study revealed that V. parahaemolyticus was most resistant to sulfamoxazole, rifampicin, and erythromycin, with resistance rates of 56.9%, 36.3%, and 33.3%, respectively. Flufenicol, chloramphenicol, and ofloxacin susceptibility rates were 97.1%, 94.1%, and 92.2%, respectively. In all, 46% of the bacteria tested positive for multi-drug resistance. The virulence gene test revealed that all bacteria lacked the tdh and trh genes. Furthermore, 91.84% and 52.04% of the isolates were largely mediated by cat and sulII, respectively, with less than 5% resistance to aminoglycosides and macrolides. There was a clear mismatch between the antimicrobial resistance phenotypes and genotypes, indicating the complexities of V. parahaemolyticus resistance. | 2024 | 38257979 |
| 1323 | 6 | 0.9927 | Detection of antibiotic resistant enterococci and Escherichia coli in free range Iberian Lynx (Lynx pardinus). Thirty fecal samples from wild specimens of Iberian lynx were collected and analyzed for Enterococcus spp. (27 isolates) and Escherichia coli (18 isolates) recovery. The 45 isolates obtained were tested for antimicrobial resistance, molecular mechanisms of resistance, and presence of virulence genes. Among the enterococci, Enterococcus faecium and Enterococcus hirae were the most prevalent species (11 isolates each), followed by Enterococcus faecalis (5 isolates). High percentages of resistance to tetracycline and erythromycin (33% and 30%, respectively) were detected among enterococcal isolates. The tet(M) and/or tet(L), erm(B), aac(6')-Ie-aph(2″)-Ia, ant(6)-Ia, or aph(3')-IIIa genes were detected among resistant enterococci. Virulence genes were detected in one E. faecalis isolate (cpd, cylB, and cylL) and one E. hirae isolate (cylL). High percentages of resistance were detected in E. coli isolates to tetracycline (33%), streptomycin (28%), nalidixic acid (28%), and sulfamethoxazole-trimethoprim (SXT, 22%). Additionally, the blaTEM, tet(A), aadA, cmlA, and different combinations of sul genes were detected among most ampicillin, tetracycline, streptomycin, chloramphenicol and SXT-resistant isolates, respectively. Two isolates contained a class 1 integron with the gene cassette arrays dfrA1 + aadA1 and dfrA12 + aadA2. The E. coli isolates were ascribed to phylo-groups A (n=5); B1 (n=4); B2 (n=6), and D (n=3), with the virulence gene fimA present in all E. coli isolates. This study found resistance genes in wild specimens of Iberian lynx. Thus, it is important to notice that multiresistant bacteria have reached species as rare and completely non-synanthropic as the Iberian lynx. Furthermore, the susceptibility of this endangered species to bacterial infection may be affected by the presence of these virulence and resistance genes. | 2013 | 23588135 |
| 1265 | 7 | 0.9927 | Coagulase-negative staphylococci (CoNS) isolated from ready-to-eat food of animal origin--phenotypic and genotypic antibiotic resistance. The aim of this work was to study the pheno- and genotypical antimicrobial resistance profile of coagulase negative staphylococci (CoNS) isolated from 146 ready-to-eat food of animal origin (cheeses, cured meats, sausages, smoked fishes). 58 strains were isolated, they were classified as Staphylococcus xylosus (n = 29), Staphylococcus epidermidis (n = 16); Staphylococcus lentus (n = 7); Staphylococcus saprophyticus (n = 4); Staphylococcus hyicus (n = 1) and Staphylococcus simulans (n = 1) by phenotypic and genotypic methods. Isolates were tested for resistance to erythromycin, clindamycin, gentamicin, cefoxitin, norfloxacin, ciprofloxacin, tetracycline, tigecycline, rifampicin, nitrofurantoin, linezolid, trimetoprim, sulphamethoxazole/trimethoprim, chloramphenicol, quinupristin/dalfopristin by the disk diffusion method. PCR was used for the detection of antibiotic resistance genes encoding: methicillin resistance--mecA; macrolide resistance--erm(A), erm(B), erm(C), mrs(A/B); efflux proteins tet(K) and tet(L) and ribosomal protection proteins tet(M). For all the tet(M)-positive isolates the presence of conjugative transposons of the Tn916-Tn1545 family was determined. Most of the isolates were resistant to cefoxitin (41.3%) followed by clindamycin (36.2%), tigecycline (24.1%), rifampicin (17.2%) and erythromycin (13.8%). 32.2% staphylococcal isolates were multidrug resistant (MDR). All methicillin resistant staphylococci harboured mecA gene. Isolates, phenotypic resistant to tetracycline, harboured at least one tetracycline resistance determinant on which tet(M) was most frequent. All of the isolates positive for tet(M) genes were positive for the Tn916-Tn1545 -like integrase family gene. In the erythromycin-resistant isolates, the macrolide resistance genes erm(C) or msr(A/B) were present. Although coagulase-negative staphylococci are not classical food poisoning bacteria, its presence in food could be of public health significance due to the possible spread of antibiotic resistance. | 2015 | 25475289 |
| 5404 | 8 | 0.9926 | Characterization of tetracycline resistance lactobacilli isolated from swine intestines at western area of Taiwan. To investigate the frequency of tetracycline resistance (Tet-R) lactobacilli in pig intestines, a total of 256 pig colons were analyzed and found to contain typical colonies of Tet-R lactic acid bacteria in every sample, ranging from 3.2 × 10(3) to 6.6 × 10(5) CFU/cm(2). From these samples, a total of 159 isolates of Tet-R lactobacilli were obtained and identified as belonging to 11 species, including Lactobacillus reuteri, Lactobacillus amylovorus, Lactobacillus salivarius, Lactobacillus plantarum, Lactobacillus ruminis, Lactobacillus kefiri, Lactobacillus fermentum, Lactobacillus sakei, Lactobacillus coryniformis, Lactobacillus parabuchneri and Lactobacillus letivazi. Based on the EFSA (2008) breakpoints, all isolates, after MIC analysis, were qualified as Tet-R, from which the significant high Tet-R MIC(50) and MIC(90) values indicated an ecological distribution of Tet-R lactobacilli mostly with high resistance potency in pig colons. PCR-detection identified 5 tet genes in these isolates, the most predominant one being tet (W), followed by tet (M), (L), (K), and (Q). Their detection rates were 82.0%, 22.5%, 14.4%, 8.1% and 0.9%, respectively. Noteworthily, isolates of the same species carrying identical tet gene(s) usually had a wide different MIC values. Furthermore, strain-subtyping of these isolates by REP-PCR demonstrated a notable genotypic biodiversity % (average = 62%). | 2011 | 21906691 |
| 5399 | 9 | 0.9926 | Characterisation and transferability of antibiotic resistance genes from lactic acid bacteria isolated from Irish pork and beef abattoirs. Lactic acid bacteria isolated from Irish pork and beef abattoirs were analysed for their susceptibility to antimicrobials. Thirty-seven isolates (12 enterococci, 10 lactobacilli, 8 streptococci, 3 lactococci, 2 Leuconostoc, and 2 pediococci) were examined for phenotypic resistance using the E-test and their minimum inhibitory concentration to a panel of six antibiotics (ampicillin, chloramphenicol, erythromycin, streptomycin, tetracycline, and vancomycin) was recorded. The corresponding genetic determinants responsible were characterised by PCR. Also, the transferability of these resistance markers was assessed in filter mating assays. Of the 37 isolates, 33 were found to be resistant to one or more antibiotics. All strains were susceptible to ampicillin and chloramphenicol. The erm(B) and msrA/B genes were detected among the 11 erythromycin-resistant strains of enterococci, lactobacilli, and streptococci. Two tetracycline-resistant strains, Lactobacillus plantarum and Leuconostoc mesenteroides spp., contained tet(M) and tet(S) genes respectively. Intrinsic streptomycin resistance was observed in lactobacilli, streptococci, lactococci and Leuconostoc species; none of the common genetic determinants (strA, strB, aadA, aadE) were identified. Four of 10 strains of Enterococcus faecium were resistant to vancomycin; however, no corresponding genetic determinants for this phenotype were identified. Enterococcus faecalis strains were susceptible to vancomycin. L. plantarum, L. mesenteroides and Pediococcus pentosaceus were intrinsically resistant to vancomycin. Transfer of antibiotic resistance determinants was demonstrated in one strain, wherein the tet(M) gene of L. plantarum (23) isolated from a pork abattoir was transferred to Lactococcus lactis BU-2-60 and to E. faecalis JH2-2. This study identified the presence of antibiotic resistance markers in Irish meat isolates and, in one example, resistance was conjugally transferred to other LAB strains. | 2010 | 20074643 |
| 1321 | 10 | 0.9925 | Antimicrobial Resistance and Resistance Genes in Aerobic Bacteria Isolated from Pork at Slaughter. The aim of this study was to investigate the phenotypic and genotypic antimicrobial resistance, integrons, and transferability of resistance markers in 243 aerobic bacteria recovered from pork at slaughter in the People's Republic of China. The organisms belonged to 22 genera of gram-negative bacteria (92.2%) and gram-positive bacteria (7.8%). High levels of resistance were detected to tetracycline, trimethoprim-sulfamethoxazole, and ampicillin (36.2 to 54.3%), and lower levels were detected to nitrofurantoin, cefotaxime, gentamicin, ciprofloxacin, and chloramphenicol (7.8 to 29.2%). Across species, genes conferring antimicrobial resistance were observed with the following frequencies: blaTEM, 40.7%; blaCMY-2, 15.2%; blaCTX-M, 11.5%; sul2, 27.2%; sul1, 14.4%; tet(A), 5.4%; tet(L), 5.4%; tet(M), 5.0%; tet(E), 3.7%; tet(C), 3.3%; tet(S), 2.5%; and tet(K), 0.8%. Various antimicrobial resistance genes were found in new carriers: blaTEM in Lactococcus garvieae, Myroides odoratimimus, Aeromonas hydrophila, Staphylococcus sciuri, Raoultella terrigena, Macrococcus caseolyticus, Acinetobacter ursingii, Sphingobacterium sp., and Oceanobacillus sp.; blaCMY-2 in Lactococcus lactis, Klebsiella oxytoca, Serratia marcescens, Acinetobacter baumannii, and Myroides phaeus; tet(L) in M. caseolyticus; sul1 in Vibrio cincinnatiensis; sul2 in Acinetobacter bereziniae, Acinetobacter johnsonii, and V. cincinnatiensis; and the class 1 integron and gene cassette aadA2 in V. cincinnatiensis. Approximately 6.6% of isolates contained class 1 integrons, and one isolate harbored class 2 integrons. Plasmid associated intI1 and androgen receptor- encoding genes were transferred into Escherichia coli J53 and E. coli DH5α by conjugation and transformation experiments, respectively. Our study highlights the importance of aerobic bacteria from pork as reservoirs for antimicrobial resistance genes and mobile genetic elements that can readily be transferred intra- and interspecies. | 2016 | 27052863 |
| 1264 | 11 | 0.9925 | Characterization of mannitol-fermenting methicillin-resistant staphylococci isolated from pigs in Nigeria. This study was conducted to determine the species distribution, antimicrobial resistance pheno- and genotypes and virulence traits of mannitol-positive methicillin-resistant staphylococci (MRS) isolated from pigs in Nsukka agricultural zone, Nigeria. Twenty mannitol-positive methicillin-resistant coagulase-negative staphylococcal (MRCoNS) strains harboring the mecA gene were detected among the 64 Staphylococcus isolates from 291 pigs. A total of 4 species were identified among the MRCoNS isolates, namely, Staphylococcus sciuri (10 strains), Staphylococcus lentus (6 strains), Staphylococcus cohnii (3 strains) and Staphylococcus haemolyticus (one strain). All MRCoNS isolates were multidrug-resistant. In addition to β-lactams, the strains were resistant to fusidic acid (85%), tetracycline (75%), streptomycin (65%), ciprofloxacin (65%), and trimethoprim/sulphamethoxazole (60%). In addition to the mecA and blaZ genes, other antimicrobial resistance genes detected were tet(K), tet(M), tet(L), erm(B), erm(C), aacA-aphD, aphA3, str, dfrK, dfrG, cat pC221, and cat pC223. Thirteen isolates were found to be ciprofloxacin-resistant, and all harbored a Ser84Leu mutation within the QRDR of the GyrA protein, with 3 isolates showing 2 extra substitutions, Ser98Ile and Arg100Lys (one strain) and Glu88Asp and Asp96Thr (2 strains). A phylogenetic tree of the QRDR nucleotide sequences in the gyrA gene revealed a high nucleotide diversity, with several major clusters not associated with the bacterial species. Our study highlights the possibility of transfer of mecA and other antimicrobial resistance genes from MRCoNS to pathogenic bacteria, which is a serious public health and veterinary concern. | 2015 | 26413075 |
| 5412 | 12 | 0.9924 | Molecular basis of resistance to macrolides and other antibiotics in commensal viridans group streptococci and Gemella spp. and transfer of resistance genes to Streptococcus pneumoniae. We assessed the mechanisms of resistance to macrolide-lincosamide-streptogramin B (MLS(B)) antibiotics and related antibiotics in erythromycin-resistant viridans group streptococci (n = 164) and Gemella spp. (n = 28). The macrolide resistance phenotype was predominant (59.38%); all isolates with this phenotype carried the mef(A) or mef(E) gene, with mef(E) being predominant (95.36%). The erm(B) gene was always detected in strains with constitutive and inducible MLS(B) resistance and was combined with the mef(A/E) gene in 47.44% of isolates. None of the isolates carried the erm(A) subclass erm(TR), erm(A), or erm(C) genes. The mel gene was detected in all but four strains carrying the mef(A/E) gene. The tet(M) gene was found in 86.90% of tetracycline-resistant isolates and was strongly associated with the presence of the erm(B) gene. The cat(pC194) gene was detected in seven chloramphenicol-resistant Streptococcus mitis isolates, and the aph(3')-III gene was detected in four viridans group streptococcal isolates with high-level kanamycin resistance. The intTn gene was found in all isolates with the erm(B), tet(M), aph(3')-III, and cat(pC194) gene. The mef(E) and mel genes were successfully transferred from both groups of bacteria to Streptococcus pneumoniae R6 by transformation. Viridans group streptococci and Gemella spp. seem to be important reservoirs of resistance genes. | 2004 | 15328112 |
| 1329 | 13 | 0.9924 | First report of the Staphylococcus aureus isolate from subclinical bovine mastitis in the South of Brazil harboring resistance gene dfrG and transposon family Tn916-1545. The aim of this work was to identify at the molecular level the species of coagulase-positive staphylococci isolates from clinical and subclinical bovine mastitis samples in Southern Brazil, and to evaluate the antimicrobial resistance profile, as well as the presence of resistance genes. According to the PCR assay, all 31 isolates were classified as Staphylococcus aureus. The isolates were tested for resistance to penicillin, ampicillin, oxacillin, cefoxitin, cephalothin, ceftiofur, streptomycin, tobramycin, teicoplanin, erythromycin, clindamycin, enrofloxacin, sulfonamide, trimethoprim-sulfamethoxazole, trimethoprim, and tetracycline by the disk diffusion method. Most of the isolates were resistant to sulfonamide (20), followed by ampicillin and clindamycin (16). Twenty isolates were multidrug-resistant. PCR was used for the detection of several antimicrobial resistance genes (ereB, ermB, ermC, tetA, tetB, tetK, tetL, tetM, tetO, Tn916-1545, strA, strB, sul1, sul2, dfrA, dfrG, dfrK, blaZ, mecA, and mecC). The most prevalent antimicrobial resistance genes were tetK and tetL, ereB, followed by tetM, Tn916-1545 and blaZ, detected in 11, nine and four isolates, respectively. For all the tetM gene positive isolates, the presence of conjugative transposons of the Tn916-1545 family was detected. The presence of multidrug-resistant isolates, antimicrobial resistance genes and transposons suggests a potential risk of spreading multi-resistance genes to other bacteria. | 2017 | 29051059 |
| 5396 | 14 | 0.9923 | Antibiotic Resistance of Coagulase-Negative Staphylococci and Lactic Acid Bacteria Isolated from Naturally Fermented Chinese Cured Beef. This study provided phenotypic and molecular analysis of the antibiotic resistance within coagulase-negative staphylococci and lactic acid bacteria isolated from naturally fermented Chinese cured beef. A total of 49 strains were isolated by selective medium and identified at the species level by 16S rRNA gene sequencing as follows: Staphylococcus carnosus (37), Lactobacillus plantarum (6), Weissella confusa (4), Lactobacillus sakei (1), and Weissella cibaria (1). All strains were typed by random amplified polymorphic DNA fingerprinting, and their antibiotic resistances profiles to 15 antibiotics were determined as the MIC by using the agar dilution method. All the tested strains were sensitive to ampicillin, and most of them were also sensitive to penicillin, gentamycin, neomycin, norfloxacin, and ciprofloxacin with low MICs. High resistance to streptomycin, vancomycin, erythromycin, roxithromycin, lincomycin, and kanamycin was widely observed, while the resistant levels to tetracycline, oxytetracycline, and chloramphenicol varied. The presence of corresponding resistance genes in resistant isolates was investigated by PCR, with the following genes detected: tet(M) gene in 9 S. carnosus strains and 1 W. confusa strain; erm(F) gene in 10 S. carnosus strains; ere(A) gene in 6 S. carnosus strains; ere(A) gene in 4 S. carnosus strains and 1 L. plantarum strain; and str(A) gene and str(B) gene in 3 S. carnosus strains. The results indicated that multiple antibiotic resistances were common in coagulase-negative staphylococci and lactic acid bacteria strains isolated from naturally fermented Chinese cured beef. Safety analysis and risk assessment should be performed for application in meat products. | 2018 | 30485765 |
| 5394 | 15 | 0.9923 | Antibiotic susceptibility of bacteria isolated from pasteurized milk and characterization of macrolide-lincosamide-streptogramin resistance genes. The presence of antibiotic-resistant bacteria in pasteurized milk was detected by plating 18 milk samples on selective media containing beta-lactams, macrolides, or a glycopeptide. Most samples contained gram-positive bacteria that grew on agar plates containing oxacillin, erythromycin, and/or spiramycin. The disk-diffusion method confirmed resistance to erythromycin and/or spiramycin in 86 and 65% of the coryneform bacteria and Micrococcaceae tested, respectively. PCR and sequence analysis revealed the presence of an ermC gene in 2 of the 25 Micrococcaceae strains investigated for their resistance to erythromycin and/or spiramycin. None of the 14 corynebacteria strains resistant to erythromycin and/or spiramycin harbored the erm(X) gene. No gene transfer could be demonstrated between the two erm(C) staphylococcal isolates and recipient strains of Enterococcus faecalis JH2-2 or Staphylococcus aureus 80CR5. | 2005 | 15726980 |
| 1259 | 16 | 0.9923 | Tetracycline resistance potential of heterotrophic bacteria isolated from freshwater fin-fish aquaculture system. AIMS: This study investigated the tetracycline resistance potential of heterotrophic bacteria isolated from twenty-four freshwater fin-fish culture ponds in Andhra Pradesh, India. METHODS AND RESULTS: A total of 261 tetracycline resistant bacteria (tetR) were recovered from pond water, pond sediment, fish gills, fish intestine, and fish feed. Bacteria with high tetracycline resistance (tetHR) (n = 30) that were resistant to tetracycline concentrations above 128 μg mL-1 were predominantly Lactococcus garvieae followed by Enterobacter spp., Lactococcus lactis, Enterobacter hormaechei, Staphylococcus arlettae, Streptococcus lutetiensis, Staphylococcus spp., Brevundimonas faecalis, Exiguobacterium profundum, Lysinibacillus spp., Stutzerimonas stutzeri, Enterobacter cloacae, and Lactococcus taiwanensis. Resistance to 1024 μg mL-1 of tetracycline was observed in L. garvieae, S. arlettae, Enterobacter spp., B. faecalis. Tet(A) (67%) was the predominant resistance gene in tetHR followed by tet(L), tet(S), tet(K), and tet(M). At similar concentrations of exposure, tetracycline procured at the farm level (69.5% potency) exhibited lower inhibition against tetHR bacteria compared to pure tetracycline (99% potency). The tetHR bacteria showed higher cross-resistance to furazolidone (100%) followed by co-trimoxazole (47.5%) and enrofloxacin (11%). CONCLUSIONS: The maximum threshold of tetracycline resistance at 1024 μg mL-1 was observed in S. arlettae, Enterobacter spp., B. faecalis, and L. garvieae and tet(A) was the major determinant found in this study. | 2023 | 36958862 |
| 5395 | 17 | 0.9923 | Assessment of Antibiotic Susceptibility within Lactic Acid Bacteria and Coagulase-Negative Staphylococci Isolated from Hunan Smoked Pork, a Naturally Fermented Meat Product in China. The aim of this study was to evaluate the antibiotic susceptibility of lactic acid bacteria (LAB) and coagulase-negative staphylococci (CNS) strains isolated from naturally fermented smoked pork produced in Hunan, China. A total of 48 strains were isolated by selective medium and identified at the species level by 16S rRNA gene sequencing as follows: Staphylococcus carnosus (23), Lactobacillus plantarum (12), Lactobacillus brevis (10), Lactobacillus sakei (1), Weissella confusa (1), and Weissella cibaria (1). All strains were typed by RAPD-PCR, and their susceptibility to 15 antibiotics was determined and expressed as the minimum inhibitory concentration (MIC) using agar dilution method. High resistance to penicillin G, streptomycin, gentamycin, vancomycin, chloramphenicol, norfloxacin, ciprofloxacin, kanamycin, and neomycin was found among the isolates. All the strains were sensitive to ampicillin, while the susceptibility to tetracycline, oxytetracycline, erythromycin, lincomycin, and roxithromycin varied. The presence of relevant resistance genes was investigated by PCR and sequencing, with the following genes detected: str(A), str(B), tet(O), tet(M), ere(A), and catA. Eleven strains, including 3 S. carnosus, 6 L. plantarum, and 2 L. brevis, harbored more than 3 antibiotic resistance genes. Overall, multiple antibiotic resistance patterns were widely observed in LAB and S. carnosus strains isolated from Hunan smoked pork. Risk assessment should be carried out with regard to the safe use of LAB and CNS in food production. PRACTICAL APPLICATION: We evaluated the antibiotic resistance of lactic acid bacteria and coagulase-negative staphylococci strains isolated from Chinese naturally fermented smoked pork. Our results may provide important data on establishing breakpoint standards for LAB and CNS and evaluating the safety risk of these strains for commercial use. | 2018 | 29786847 |
| 832 | 18 | 0.9922 | Development of antibiotic resistance in the ocular Pseudomonas aeruginosa clone ST308 over twenty years. Corneal infection caused by a bacteria Pseudomonas aeruginosa is common cause of ocular morbidity. Increasing antibiotic resistance by ocular P. aeruginosa is an emerging concern. In this study the resistome of ocular isolates of Pseudomonas aeruginosa clone ST308 isolated in India in 1997 (PA31, PA32, PA33, PA35 and PA37) and 2018 (PA198 and PA219) were investigated. All the isolates of ST308 had >95% nucleotide similarity. The isolates from 2018 had larger genomes, coding sequences, accessory and pan genes compared to the older isolates from 1997. The 2018 isolate PA219 was resistant to all antibiotics except polymyxin B, while the 2018 isolate PA198 was resistant to ciprofloxacin, levofloxacin, gentamicin and tobramycin. Among the isolates from 1997, five were resistant to gentamicin, tobramycin and ciprofloxacin, four were resistant to levofloxacin while two were resistant to polymyxin B. Twenty-four acquired resistance genes were present in the 2018 isolates compared to 11 in the historical isolates. All isolates contained genes encoding for aminoglycoside (aph(6)-Id, aph(3')-lIb, aph(3″)-Ib), beta-lactam (blaPAO), tetracycline (tet(G)), fosfomycin (fosA), chloramphenicol (catB7), sulphonamide (sul1), quaternary ammonium (qacEdelta1) and fluoroquinolone (crpP) resistance. Isolate PA198 possessed aph(3')-VI, rmtD2, qnrVC1, blaOXA-488, blaPME-1, while PA219 possessed aadA1, rmtB, qnrVC1, aac(6')-Ib-cr, blaTEM-1B, blaVIM-2, blaPAO-1, mph(E), mph(A), msr(E). In both recent isolates qnrVC1 was present in Tn3 transposon. In 219 blaTEM-1 was carried on a transposon and blaOXA-10 on a class 1 integron. There were no notable differences in the number of single nucleotide polymorphisms, but recent isolates carried more insertions and deletions in their genes. These findings suggest that genomes of P. aeruginosa ocular clonal strains with >95% nucleotide identity isolated twenty years apart had changed over time with the acquisition of resistance genes. The pattern of gene mutations also varied with more insertions and deletions in their chromosomal genes which confer resistance to antibiotics. | 2021 | 33610601 |
| 1375 | 19 | 0.9922 | Characterization of integrons and their cassettes in Escherichia coli and Salmonella isolates from poultry in Korea. Ninety-nine Escherichia coli and 33 Salmonella isolates were assessed for antimicrobial susceptibility (disc diffusion test). Sulfonamide and tetracycline resistance genes were identified through PCR, and class 1 and class 2 integrons with resistance gene cassettes were identified with PCR followed by sequencing. Salmonella (63.6%) and E. coli (85.8%) isolates were multidrug resistant (resistance to 3 or more antimicrobials), and the highest incidences of resistance were observed for tetracycline, nalidixic acid, and sulfamethoxazole. The sul1, sul2, tetA, and tetB resistance determinant genes were predominant in E. coli, whereas only sul2 and tetA were identified in Salmonella isolates. In the E. coli isolates, 54 (54.5%) class 1 integrons, 6 (6.1%) class 2 integrons, and 5 (5.1%) class 1 and class 2 integrons together were detected, whereas only 3 (9.1%) integrons were found in the Salmonella serovars. Around 87% of the integrons in E. coli harbored resistance gene cassettes conferring resistance to streptomycin/spectinomycin (aadA, aminoglycoside resistance gene), trimethoprim (dfrA, dihydrofolate reductase gene), streptothricin [sat1 and sat2 (streptothricin acetyltransferase), and estX (putative esterases)]. The most common gene cassettes were aadA1+dfrA1 and dfrA1+sat2+aadA1 in class 1 and class 2 integrons, respectively. Other cassettes including aadA5+dfrA7, dfrA12+aadA2, aadA2+aadA1+dfrA12, and aadA5+aadA2/dfrA7 were also identified. Among the Salmonella serovars, Salmonella Malmoe harbored aadA1+dfrA1 and dfrA12+sat2+aadA1 genes. The aadA1, aadA2, sat2, and dfrA1 had wide variation in similarity among themselves and from previously reported genes worldwide. The diverse gene cassettes could be responsible for the prominent resistance profiles observed and a potential source for dissemination of antimicrobial resistance determinants to other bacteria. | 2013 | 24135609 |