# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 2169 | 0 | 0.9951 | E-test antibiotics susceptibility of strict anaerobic bacteria. The E-test is convenient for testing susceptibility of anaerobes. From September 1998 to September 1999, 194 strains (105 Gram-positive bacteria, 89 Gram-negative bacteria) of clinically relevant samples were tested against five antibiotics benzylpenicillin, amoxicillin-clavulanic acid, clindamycin, metronidazole and imipenem on blood agar plates. Resistance to benzyl penicillin is widespread and Gram-negative bacteria and resistance to amoxicillin-clavulanic acid is exceptional. Metronidazole is very effective against anaerobes except non-spore-forming aerotolerant Gram-positive rods and Peptostreptococcus micros. | 2003 | 16887712 |
| 5427 | 1 | 0.9950 | PCR-based detection of resistance genes in anaerobic bacteria isolated from intra-abdominal infections. Little information is available on the distribution of antimicrobial resistance genes in anaerobes in Japan. To understand the background of antimicrobial resistance in anaerobes involved in intra-abdominal infections, we investigated the distribution of eight antimicrobial resistance genes (cepA, cfiA, cfxA, ermF, ermB, mefA, tetQ, and nim) and a mutation in the gyrA gene in a total of 152 organisms (Bacteroides spp., Prevotella spp., Fusobacterium spp., Porphyromonas spp., Bilophila wadsworthia, Desulfovibrio desulfuricans, Veillonella spp., gram-positive cocci, and non-spore-forming gram-positive bacilli) isolated between 2003 and 2004 in Japan. The cepA gene was distributed primarily in Bacteroides fragilis. Gene cfxA was detected in about 9 % of the Bacteroides isolates and 75 % of the Prevotella spp. isolates and did not appear to contribute to cephamycin resistance. Two strains of B. fragilis contained the metallo-β-lactamase gene cfiA, but they did not produce the protein product. Gene tetQ was detected in about 81, 44, and 63 % of B. fragilis isolates, other Bacteroides spp., and Prevotella spp. isolates, respectively. The ermF gene was detected in 25, 13, 56, 64, and 16 % of Bacteroides spp., Prevotella spp., Fusobacterium spp., B. wadsworthia, and anaerobic cocci, respectively. Gene mefA was found in only 10 % of the B. fragilis strains and 3 % of the non-B. fragilis strains. Genes nim and ermB were not detected in any isolate. Substitution at position 82 (Ser to Phe) in gyrA was detected in B. fragilis isolates that were less susceptible or resistant to moxifloxacin. This study is the first report on the distribution of resistance genes in anaerobes isolated from intra-abdominal infections in Japan. We expect that the results might help in understanding the resistance mechanisms of specific anaerobes. | 2013 | 23338012 |
| 2437 | 2 | 0.9946 | Periodontal pathogens and tetracycline resistance genes in subgingival biofilm of periodontally healthy and diseased Dominican adults. OBJECTIVE: The objective of this study was to compare the periodontopathogen prevalence and tetracycline resistance genes in Dominican patients with different periodontal conditions. METHODS: Seventy-seven samples were collected from healthy, gingivitis, chronic (CP) and aggressive (AgP) periodontitis patients. Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Prevotella intermedia, Parvimonas micra, Eikenella corrodens and Dialister pneumosintes and 11 resistance genes were studied by PCR. P. gingivalis fimA genotype was determined. RESULTS: In healthy patients, P. micra and P. intermedia were the most and least frequently detected, respectively. T. forsythia and E. corrodens appeared in 100% of gingivitis patients. Red complex, D. pneumosintes and E. corrodens were significantly more prevalent in CP compared to healthy patients. F. nucleatum and T. denticola were detected more frequently in AgP. A. actinomycetemcomitans was the most rarely observed in all groups. The fimA II genotype was the most prevalent in periodontitis patients. Seven tetracycline-resistant genes were detected. tet(Q), tet(32) and tet(W) showed the greatest prevalence. tet(32) was significantly more prevalent in CP than in healthy patients. CONCLUSIONS: Red complex bacteria and D. pneumosintes were significantly the most prevalent species among periodontitis patients. T. forsythia was the most frequently detected in this population. To our knowledge, this is the first study describing the tet(32) gene in subgingival biofilm from healthy and periodontally diseased subjects. CLINICAL RELEVANCE: This study contributes to the knowledge on the subgingival microbiota and its resistance genes of a scarcely studied world region. Knowing the prevalence of resistance genes could impact on their clinical prescription and could raise awareness to the appropriate use of antibiotics. | 2016 | 26121972 |
| 1297 | 3 | 0.9946 | Antimicrobial resistance, prevalence of resistance genes, and molecular characterization in intestinal Bacteroides fragilis group isolates. Since the level of antimicrobial resistance in Bacteroides fragilis has increased, monitoring the antimicrobial susceptibility could be necessary. The objectives of this study were to (i) investigate the prevalence of species, the occurrence of reduced antimicrobial susceptibility (E-test method), and antibiotic resistance genes in the B. fragilis group and (ii) evaluate the prevalence of enterotoxigenic B. fragilis and the distribution of bft gene subtypes in hospitalized patients. As many as 475 isolates out of 250 stool samples were detected to be B. fragilis group by using conventional biochemical tests (API-32A system) and multiplex-PCR. In addition, 48.2%, 13.9%, 76.6%, and 1.2% of B. fragilis group isolates were resistant (according to EUCAST breakpoint) to piperacillin-tazobactam, meropenem, clindamycin, and metronidazole, respectively. Six metronidazole-resistant strains were isolated; B. fragilis (n: 3), B. thetaiotaomicron, B. vulgates, and B. ovatus. The presence of the cfiA, cepA, ermF, and nim genes was observed in 3.8%, 15.9%, 34.1%, and 0.7% of the B. fragilis isolates, respectively. One hundred thirty-two B. fragilis isolates (27.8%)and 21 B fragilis isolates (15.9%) turned out to be bft gene positive by multiplex-PCR; eleven isolates (52.4%) harbored bft-1, eight isolates (38%) harbored bft-2 isotypes, and two isolates (9.5%) harbored bft-3 isotype (16.66%). These bacteria harbor antimicrobial resistance genes that could be transferred to other susceptible intestinal strains. Further investigations on lineage analysis are needed for a better understanding of these bacteria in Iran. | 2019 | 30803024 |
| 5426 | 4 | 0.9946 | First Report of Antibiotic Resistance Markers cfiA and nim Among Bacteroides fragilis Group Strains in Ecuadorian Patients. In recent years, increasing resistance of Bacteroides fragilis to several antibiotics has been reported in different countries. The aim of this study was to evaluate the antibiotic resistance profiles of Bacteroides spp. isolated from clinical samples by phenotypic and molecular methods. A total of 40 nonrepetitive isolates of the B. fragilis group were studied from 2018 to 2019. The species was identified by API 20A system. The minimum inhibitory concentrations (MICs) were determined by Sensititre anaerobe MIC plate. The presence of the nim and cfiA genes was checked by conventional PCR. The association between genes and insertion sequence (IS) was performed by whole genome sequencing. Eleven isolates were categorized as metronidazole-resistant and only 2 isolates harbored the nim gene. Five isolates were imipenem-resistant, but cfiA gene was detected in two isolates. cfiA gene was closely related to the cfiA-4 allele and associated with IS614B. The nim gene was not related to any nim gene type and was considered a new variant named nimL. IS612 was found upstream of nimL gene. In view of the scarcity of data on B. fragilis, there is a need to surveil antibiotic resistance levels and molecular mechanisms to implement better antimicrobial therapies against this important group of bacteria. | 2023 | 37733248 |
| 1256 | 5 | 0.9946 | Prevalence of antimicrobial resistant genes in Bacteroides spp. isolated in Oita Prefecture, Japan. INTRODUCTION: Bacteroides spp. are the most common anaerobic bacteria isolated from the human gastrointestinal tract. Several resistant genes are present in Bacteroides spp. However, most studies have focused on the prevalence of the cfiA gene in Bacteroides fragilis alone. We assessed the susceptibility to antimicrobial agents and the prevalence of cepA, cfiA, cfxA, ermF, nim, and tetQ genes in Bacteroides strains isolated from clinical specimens in our hospital. METHODS: We isolated 86 B. fragilis and 58 non-fragilis Bacteroides strains from human clinical specimens collected from January 2011 to November 2021. Resistance against piperacillin (PIPC), cefotaxime (CTX), cefepime (CFPM), meropenem (MEPM), clindamycin, and minocycline was determined. RESULTS: The resistant rates of penicillins and cephalosporins in non-fragilis isolates were significantly higher than those in B. fragilis isolates. In B. fragilis isolates, the resistant rates of PIPC, CTX, and CFPM in cfxA-positive isolates were significantly higher than those in cfxA-negative isolates (71% vs. 16%, 77% vs. 19%, and 77% vs. 30%, respectively). Thirteen B. fragilis isolates harbored the cfiA gene, two of which were resistant to MEPM. Six of the 13 cfiA-positive B. fragilis isolates were heterogeneously resistant to MEPM. CONCLUSION: It is important to evaluate the use of MEPM as empirical therapy for Bacteroides spp. infections, considering the emergence of carbapenem resistance during treatment, existence of MEPM-resistant strains, and heterogeneous resistance. | 2023 | 36473684 |
| 829 | 6 | 0.9945 | Loop-mediated isothermal amplification assay for 16S rRNA methylase genes in Gram-negative bacteria. Using the loop-mediated isothermal amplification (LAMP) method, we developed a rapid assay for detection of 16S rRNA methylase genes (rmtA, rmtB, and armA), and investigated 16S rRNA methylase-producing strains among clinical isolates. Primer Explorer V3 software was used to design the LAMP primers. LAMP primers were prepared for each gene, including two outer primers (F3 and B3), two inner primers (FIP and BIP), and two loop primers (LF and LB). Detection was performed with the Loopamp DNA amplification kit. For all three genes (rmtA, rmtB, and armA), 10(2) copies/tube could be detected with a reaction time of 60 min. When nine bacterial species (65 strains saved in National Institute of Infectious Diseases) were tested, which had been confirmed to possess rmtA, rmtB, or armA by PCR and DNA sequencing, the genes were detected correctly in these bacteria with no false negative or false positive results. Among 8447 clinical isolates isolated at 36 medical institutions, the LAMP method was conducted for 191 strains that were resistant to aminoglycosides based on the results of antimicrobial susceptibility tests. Eight strains were found to produce 16S rRNA methylase (0.09%), with rmtB being identified in three strains (0.06%) of 4929 isolates of Enterobacteriaceae, rmtA in three strains (0.10%) of 3284 isolates of Pseudomonas aeruginosa, and armA in two strains (0.85%) of 234 isolates of Acinetobacter spp. At present, the incidence of strains possessing 16S rRNA methylase genes is very low in Japan. However, when Gram-negative bacteria showing high resistance to aminoglycosides are isolated by clinical laboratories, it seems very important to investigate the status of 16S rRNA methylase gene-harboring bacilli and monitor their trends among Japanese clinical settings. | 2014 | 25179393 |
| 1484 | 7 | 0.9944 | Use of a commercial PCR-based line blot method for identification of bacterial pathogens and the mecA and van genes from BacTAlert blood culture bottles. In this study, the PCR-based DNA strip assay GenoType BC for the identification of bacteria and the resistance genes mecA, vanA, vanB, vanC1, and vanC2/3 directly from positive BacTAlert blood culture bottles was evaluated in a multicenter study. Of a total of 511 positive blood cultures, correct identification percentages for Gram-negative bacteria, Gram-positive bacteria, and the mecA gene were 96.1%, 89.9%, and 92.9%, respectively. Results were available 4 h after growth detection. | 2012 | 22075585 |
| 1483 | 8 | 0.9944 | Clinical Evaluation of the iCubate iC-GPC Assay for Detection of Gram-Positive Bacteria and Resistance Markers from Positive Blood Cultures. The iC-GPC Assay (iCubate, Huntsville, AL) is a qualitative multiplex test for the detection of five of the most common Gram-positive bacteria (Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Enterococcus faecalis, and Enterococcus faecium) responsible for bacterial bloodstream infections, performed directly from positive blood cultures. The assay also detects the presence of the mecA, vanA, and vanB resistance determinants. This study comparatively evaluated the performance of the iC-GPC Assay against the Verigene Gram-positive blood culture (BC-GP) assay (Luminex Corp., Austin, TX) for 1,134 patient blood culture specimens positive for Gram-positive cocci. The iC-GPC Assay had an overall percent agreement with the BC-GP assay of 95.5%. Discordant specimens were further analyzed by PCR and a bidirectional sequencing method. The results indicate that the iC-GPC Assay together with the iCubate system is an accurate and reliable tool for the detection of the five most common Gram-positive bacteria and their resistance markers responsible for bloodstream infections. | 2018 | 29899000 |
| 2092 | 9 | 0.9944 | Antibacterial activities of multi drug resistant Myroides odoratimimus bacteria isolated from adult flesh flies (Diptera: sarcophagidae) are independent of metallo beta-lactamase gene. Sarcophagidae) are well known cause of myiasis and their gut bacteria have never been studied for antimicrobial activity against bacteria. Antimicrobial studies of Myroides spp. are restricted to nosocomial strains. A Gram-negative bacterium, Myroides sp., was isolated from the gut of adult flesh flies (Sarcophaga sp.) and submitted to evaluation of nutritional parameters using Biolog GN, 16S rRNA gene sequencing, susceptibility to various antimicrobials by disc diffusion method and detection of metallo β-lactamase genes (TUS/MUS). The antagonistic effects were tested on Gram-negative and Gram-positive bacteria isolated from human clinical specimens, environmental samples and insect mid gut. Bacterial species included were Aeromonas hydrophila, A. culicicola, Morganella morganii subsp. sibonii, Ochrobactrum anthropi, Weissella confusa, Escherichia coli, Ochrobactrum sp., Serratia sp., Kestersia sp., Ignatzschineria sp., Bacillus sp. The Myroides sp. strain was resistant to penicillin-G, erythromycin, streptomycin, amikacin, kanamycin, gentamycin, ampicillin, trimethoprim and tobramycin. These strain showed antibacterial action against all bacterial strains except W. confusa, Ignatzschineria sp., A. hydrophila and M. morganii subsp. sibonii. The multidrug resistance of the strain was similar to the resistance of clinical isolates, inhibiting growth of bacteria from clinical, environmental and insect gut samples. The metallo β-lactamase (TUS/MUS) genes were absent, and resistance due to these genes was ruled out, indicating involvement of other secretion machinery. | 2008 | 24031236 |
| 5413 | 10 | 0.9943 | First detection of the staphylococcal trimethoprim resistance gene dfrK and the dfrK-carrying transposon Tn559 in enterococci. The trimethoprim resistance gene dfrK has been recently described in Staphylococcus aureus, but so far has not been found in other bacteria. A total of 166 enterococci of different species (E. faecium, E. faecalis, E. hirae, E. durans, E. gallinarum, and E. casseliflavus) and origins (food, clinical diseases in humans, healthy humans or animals, and sewage) were studied for their susceptibility to trimethoprim as determined by agar dilution (European Committee on Antimicrobial Susceptibility Testing) and the presence of (a) the dfrK gene and its genetic environment and (b) other dfr genes. The dfrK gene was detected in 49% of the enterococci (64% and 42% of isolates with minimum inhibitory concentrations of ≥2 mg/L or ≤1 mg/L, respectively). The tet(L)-dfrK linkage was detected in 21% of dfrK-positive enterococci. The chromosomal location of the dfrK gene was identified in one E. faecium isolate in which the dfrK was not linked to tet(L) gene but was part of a Tn559 element, which was integrated in the chromosomal radC gene. This Tn559 element was also found in 14 additional isolates. All combinations of dfr genes were detected among the isolates tested (dfrK, dfrG, dfrF, dfrK+dfrG, dfrK+dfrF, dfrF+dfrG, and dfrF+dfrG+dfrK). The gene dfrK gene was found together with other dfr genes in 58% of the tested enterococci. This study suggested an exchange of the trimethoprim resistance gene dfrK between enterococci and staphylococci, as previously observed for the trimethoprim resistance gene dfrG. | 2012 | 21718151 |
| 5394 | 11 | 0.9943 | 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 |
| 2141 | 12 | 0.9943 | Identification of oral anaerobic bacteria and the beta-lactamase resistance genes from Iranian patients with periodontitis. OBJECTIVES: The dysbiosis of bacteria and horizontal transfer of antibiotic resistance genes (ARGs) could be highly problematic particularly in the oral environment. Here, we aimed to identify the anaerobic species from patients with periodontitis and to screen the isolates for the β-lactamase resistance genes, bla(TEM), cfxA, its variants, and mobA. METHODS: The 129 samples from periodontal pockets were subjected to anaerobic culture, followed by 16S rRNA gene sequencing, PCR assays for the cfxA, bla(TEM), and mobA. The minimum inhibitory concentration (MIC) of amoxicillin, ampicillin, amoxicillin/clavulanate, ampicillin/sulbactam, and cefixime was determined against CfxA producing isolates using MIC Test Strips. RESULTS: The species with frequency higher than 10% were Lactobacillus spp. (26.3%), Streptococcus spp. (18.8%), Leptotrichia wadei (14%) and Veillonella spp. (11.4%). The bla(TEM) was not found in any of the isolates whereas cfxA was found in 12.5% of isolates including V. parvula, V. rogosae, Prevotella nigrescens and Campylobacter concisus. Of CfxA variants, CfxA2 (90%) was the most frequent one. Among the CfxA producing isolates, the resistance to ampicillin and amoxicillin was observed only in two isolates of P. nigrescens and V. rogosae. CONCLUSIONS: This study showed that various anaerobes species may be involved in the development of periodontitis. Of them, Prevotella and Veillonella species were found to commonly carry cfxA even though they are susceptible to beta-lactams and its combination. | 2022 | 35026418 |
| 5397 | 13 | 0.9942 | Antimicrobial Resistance of Seventy Lactic Acid Bacteria Isolated from Commercial Probiotics in Korea. In this study, lactic acid bacteria were isolated from 21 top-selling probiotic products on Korean market and their antimicrobial resistance were analyzed. A total 152 strains were claimed to be contained in these products and 70 isolates belonging to three genera (Bifidobacterium, Lactobacillus, and Lactococcus) were obtained from these products. RAPD-PCR showed diversity among isolates of the same species except for two isolates of Lacticaibacillus rhamnosus from two different products. The agar dilution method and the broth dilution method produced different MICs for several antimicrobials. With the agar dilution method, five isolates (three isolates of Bifidobacterium animalis subsp. lactis, one isolate of B. breve, one isolate of B. longum) were susceptible to all nine antimicrobials and 15 isolates were multi-drug resistant. With the broth microdilution method, only two isolates (one isolate of B. breve and one isolate of B. longum) were susceptible while 16 isolates were multi-drug resistant. In this study, only two AMR genes were detected: 1) lnu(A) in one isolate of clindamycin-susceptible and lincomycin-resistant Limosilactobacillus reuteri; and 2) tet(W) in one tetracycline-susceptible isolate of B. longum B1-1 and two tetracycline-susceptible isolates and three tetracycline resistant isolates of B. animalis subsp. lactis. Transfer of these two genes via conjugation with a filter mating technique was not observed. These results suggest a need to monitor antimicrobial resistance in newly registered probiotics as well as probiotics with a long history of use. | 2023 | 36746921 |
| 5396 | 14 | 0.9942 | 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 |
| 5940 | 15 | 0.9942 | In vitro activities of spectinomycin and comparator agents against Pasteurella multocida and Mannheimia haemolytica from respiratory tract infections of cattle. OBJECTIVES: Prior to the renewal of spectinomycin licensing for veterinary uses in Germany, 154 Pasteurella multocida and 148 Mannheimia haemolytica strains from respiratory tract infections in cattle were investigated for their MICs of spectinomycin and other antimicrobial agents. The data obtained should serve as a baseline from which to judge the future development of resistance. Moreover, the in vitro activity of spectinomycin in comparison with other antimicrobials should be assessed. METHODS: MIC determination for all 302 strains was performed by the broth dilution method and evaluated according to NCCLS standards. MIC(50) and MIC(90) values were calculated. Strains resistant to spectinomycin were subjected to PCR assays for genes known to mediate spectinomycin resistance in Gram-negative and Gram-positive bacteria. RESULTS: With the exception of resistance to sulfamethoxazole in P. multocida and M. haemolytica, and resistance to ampicillin in M. haemolytica, an overall low level of resistance was detected. A total of 93.5% of the P. multocida and 98.6% of the M. haemolytica strains were susceptible to spectinomycin, with MIC(90)s of 32 mg/L. PCR analysis showed that none of the spectinomycin-resistant strains carried any of the aadA gene subtypes, nor the genes spc or aad(9). CONCLUSIONS: Prior to the renewal of spectinomycin, only a small number of spectinomycin-resistant strains was detected among bovine P. multocida and M. haemolytica. The genes responsible for spectinomycin resistance in these strains seemed to be different from those so far known to occur in other Gram-negative and Gram-positive bacteria. | 2004 | 14729757 |
| 5434 | 16 | 0.9942 | Can beta-lactamase resistance genes in anaerobic Gram-negative gut bacteria transfer to gut aerobes? The study was conceived with the hypothesis that human aerobic gut flora could act as a reservoir of ß-lactamases and contribute to the emergence of ß-lactam resistance by transferring ß-lactamase genes to resident anaerobes. Thus, we studied the repertoire of ß-lactam resistance determinants (ß-lactamases associated with aerobes and anaerobes) in Gram-negative anaerobes. The phenotypic resistance against ß-lactams and the presence of aerobic and anaerobic ß-lactamases were tested in Gram-negative anaerobic isolates (n = 200) by agar dilution method and targeted PCR, respectively. In addition, whole-genome sequencing (WGS) was used to study the ß-lactam resistance determinants in 4/200 multi-drug resistant (MDR) strains. The resistance to ß-lactams was as follows: imipenem (0.5%), cefoxitin (26.5%), and piperacillin-tazobactam (27.5%). None of the isolates showed the presence of ß-lactamases found in aerobic microorganisms. The presence of anaerobic ß-lactamase genes viz. cfiA, cepA, cfxA, cfiA(IS) [the intact segment containing cfiA gene (350 bp) and upstream IS elements (1.6-1.7 kb)] was detected in 10%, 9.5%, 21.5%, and 0% isolates, respectively. The WGS data showed the presence of cfiA, cfiA4, cfxA, cfxA2, cfxA3, cfxA4, cfxA5 in MDR strains. The study showed a distinct dichotomy in repertoires of ß-lactamases between aerobes and anaerobes. | 2023 | 36997726 |
| 5399 | 17 | 0.9942 | 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 |
| 2366 | 18 | 0.9942 | Vancomycin-variable enterococci in sheep and cattle isolates and whole-genome sequencing analysis of isolates harboring vanM and vanB genes. BACKGROUND: Vancomycin resistance encoded by the vanA/B/M genes in enterococci is clinically important because of the transmission of these genes between bacteria. While vancomycin resistance is determined by detecting only vanA and vanB genes by routine analyses, failure to detect vanM resistance causes vancomycin resistance to be overlooked, and clinically appropriate treatment cannot be provided. AIMS: The study aimed to examine the presence of vanM-positive enterococcal isolates in Ankara, Turkey, and to have detailed information about them with sequence analyses. METHODS: Caecal samples were collected from sheep and cattle during slaughter at different slaughterhouses in Ankara, Turkey. Enterococci isolates were identified, confirmed, and analyzed for the presence of vanA/B/M genes. Antibiotic resistance profiles of isolates were determined by the broth microdilution method. A whole genome sequence analysis of the isolates harboring the vanM and vanB genes was performed. RESULTS: 13.7% of enterococcal isolates were determined as Enterococcus faecium and Enterococcus faecalis. 15% of these isolates contained vanB, and 40% were vanM-positive. S98b and C32 isolates were determined to contain 16 CRISPR-Cas elements. 80% of the enterococci isolates were resistant to nitrofurantoin and 15% to ciprofloxacin. The first vanM-positive vancomycin-variable enterococci (VVE) isolates from food-producing animals were identified, and the S98b strain has been assigned to Genbank with the accession number CP104083.1. CONCLUSION: Therefore, new studies are needed to facilitate the identification of vanM-resistant enterococci and VVE strains. | 2023 | 38269016 |
| 5429 | 19 | 0.9941 | Antibiotic resistance pattern of Bacteroides fragilis isolated from clinical and colorectal specimens. BACKGROUND: Bacteroides fragilis is a part of the normal gastrointestinal flora, but it is also the most common anaerobic bacteria causing the infection. It is highly resistant to antibiotics and contains abundant antibiotic resistance mechanisms. METHODS: The antibiotic resistance pattern of 78 isolates of B. fragilis (22 strains from clinical samples and 56 strains from the colorectal tissue) was investigated using agar dilution method. The gene encoding Bacteroides fargilis toxin bft, and antibiotic resistance genes were targeted by PCR assay. RESULTS: The highest rate of resistance was observed for penicillin G (100%) followed by tetracycline (74.4%), clindamycin (41%) and cefoxitin (38.5%). Only a single isolate showed resistance to imipenem which contained cfiA and IS1186 genes. All isolates were susceptible to metronidazole. Accordingly, tetQ (87.2%), cepA (73.1%) and ermF (64.1%) were the most abundant antibiotic-resistant genes identified in this study. MIC values for penicillin, cefoxitin and clindamycin were significantly different among isolates with the cepA, cfxA and ermF in compare with those lacking such genes. In addition, 22.7 and 17.8% of clinical and GIT isolates had the bft gene, respectively. CONCLUSIONS: The finding of this study shows that metronidazole is highly in vitro active agent against all of B. fragilis isolates and remain the first-line antimicrobial for empirical therapy. | 2021 | 33892721 |