# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 2404 | 0 | 0.9604 | Prevalence of the Antibiotic Resistance Genes in Coagulase-Positive-and Negative-Staphylococcus in Chicken Meat Retailed to Consumers. The use of antibiotics in farm management (growing crops and raising animals) has become a major area of concern. Its implications is the consequent emergence of antibiotic resistant bacteria (ARB) and accordingly their access into the human food chain with passage of antibiotic resistance genes (ARG) to the normal human intestinal microbiota and hence to other pathogenic bacteria causative human disease. Therefore, we pursued in this study to unravel the frequency and the quinolone resistance determining region, mecA and cfr genes of methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), methicillin-resistant coagulase-negative staphylococci (MRCNS) and methicillin-susceptible coagulase-negative staphylococci (MSCNS) isolated from the retail trade of ready-to-eat raw chicken meat samples collected during 1 year and sold across the Great Cairo area. The 50 Staphylococcus isolated from retail raw chicken meat were analyzed for their antibiotic resistance phenotypic profile on 12 antibiotics (penicillin, oxacillin, methicillin, ampicillin-sulbactam, erythromycin, tetracycline, clindamycin, gentamicin, ciprofloxacin, chloramphenicol, sulfamethoxazole-trimethoprim, and vancomycin) and their endorsement of the quinolone resistance determining region, mecA and cfr genes. The isolation results revealed 50 isolates, CPS (14) and CNS (36), representing ten species (S. aureus, S. hyicus, S. epidermedius, S. lugdunensis, S. haemolyticus, S. hominus, S. schleiferi, S. cohnii, S. intermedius, and S. lentus). Twenty seven isolates were methicillin-resistant. Out of the characterized 50 staphylococcal isolates, three were MRSA but only 2/3 carried the mecA gene. The ARG that bestows resistance to quinolones, β-lactams, macrolides, lincosamides, and streptogramin B [MLS((B))] in MRSA and MR-CNS were perceived. According to the available literature, the present investigation was a unique endeavor into the identification of the quinolone-resistance-determining-regions, the identification of MRSA and MR-CNS from retail chicken meat in Egypt. In addition, these isolates might indicate the promulgation of methicillin, oxacillin and vancomycin resistance in the community and imply food safety hazards. | 2016 | 27920760 |
| 1265 | 1 | 0.9602 | 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 |
| 1263 | 2 | 0.9600 | Antimicrobial Resistance and Antimicrobial Activity of Staphylococcus lugdunensis Obtained from Two Spanish Hospitals. Staphylococcus lugdunensis is a coagulase-negative-staphylococci (CoNS) that lately has gained special attention in public health as a human pathogen and also as a bacteriocin-producer bacteria. In this study, we characterized 56 S. lugdunensis isolates recovered from human samples in two Spanish hospitals. Antimicrobial susceptibility testing was performed and antimicrobial resistance and virulence genotypes were determined. Antimicrobial activity (AA) production was evaluated by the spot-on-lawn method against 37 indicator bacteria, including multidrug-resistant (MDR) isolates, and the presence of the lugD gene coding for lugdunin bacteriocin was analyzed by PCR. The antibiotic resistance detected was as follows (% resistance/genes detected): penicillin (44.6%/blaZ), oxacillin (1.8%/mecA on SCCmec-V), erythromycin-clindamycin inducible (7.1%/erm(C), msrA), tetracycline (5.3%/tetK), gentamicin and/or tobramycin (3.6%/ant(4')-Ia, acc(6')-aph(2″)), and fosfomycin (21.4%). A MDR phenotype was detected in 5% of isolates. Twenty-one of the S. lugdunensis isolates showed susceptibility to all 20 antibiotics tested (37.5%). The screening for AA revealed 23 antimicrobial producer (AP) isolates with relevant inhibition against coagulase-positive-staphylococci (CoPS), including both methicillin-susceptible and -resistant S. aureus. The lugD gene was detected in 84% of the 56 S. lugdunensis isolates. All of the AP S. lugdunensis isolates (n = 23) carried the lugD gene and it was also detected in 24 of the non-AP isolates, suggesting different gene expression levels. One of the AP isolates stood out due to its high antimicrobial activity against more than 70% of the indicator bacteria tested, so it will be further characterized at genomic and proteomic level. | 2022 | 35893538 |
| 1259 | 3 | 0.9600 | 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 |
| 1267 | 4 | 0.9599 | Detection and characterization of methicillin-resistant and susceptible coagulase-negative staphylococci in milk from cows with clinical mastitis in Tunisia. OBJECTIVES: This study investigated prevalence of methicillin-resistant (MR) and methicillin-susceptible (MS) coagulase-negative staphylococci (CNS) and the implicated mechanisms of resistance and virulence in milk of mastitis cows. In addition, the presence of SCCmec type was analyzed in MR Staphylococcus epidermidis (MRSE). RESULTS: Three hundred milk samples from cows with clinical mastitis were obtained from 30 dairy farms in different regions of Tunisia. Sixty-eight of the 300 tested samples contained CNS strains. Various CNS species were identified, with Staphylococcus xylosus being the most frequently found (40%) followed by Staphylococcus warneri (12%). The mecA gene was present in 14 of 20 MR-CNS isolates. All of them were lacking the mecC gene. The SCCmecIVa was identified in four MRSE isolates. Most of CNS isolates showed penicillin resistance (70.6%) and 58.3% of them carried the blaZ gene. MR-CNS isolates (n = 20) showed resistance to erythromycin, tetracycline and trimethoprim-sulfametoxazole harboring different resistance genes such us erm(B), erm(T), erm(C), mph(C) or msr(A), tet(K) and dfr(A). However, a lower percentage of resistance was observed among 48 MS-CNS isolates: erythromycin (8.3%), tetracycline (6.2%), streptomycin (6.2%), clindamycin (6.2%), and trimethoprim-sulfametoxazole (2%). The Inu(B) gene was detected in one Staphylococcus xylosus strain that showed clindamycin resistance. The virulence gene tsst-1 was observed in one MR-CNS strain. DISCUSSION: Coagulase-negative staphylococci containing a diversity of antimicrobial resistance genes are frequently detected in milk of mastitis cows. This fact emphasizes the importance of identifying CNS when an intramammary infection is present because of the potential risk of lateral transfer of resistant genes among staphylococcal species and other pathogenic bacteria. | 2018 | 30077662 |
| 1264 | 5 | 0.9598 | 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 |
| 1261 | 6 | 0.9594 | Antibiotic Resistance Genes, Virulence Factors, and Biofilm Formation in Coagulase-Negative Staphylococcus spp. Isolates from European Hakes (Merluccius merluccius, L.) Caught in the Northeast Atlantic Ocean. The indiscriminate use of antibiotics has contributed to the dissemination of multiresistant bacteria, which represents a public health concern. The aim of this work was to characterize 27 coagulase-negative staphylococci (CoNS) isolated from eight wild Northeast Atlantic hakes (Merluccius merluccius, L.) and taxonomically identified as Staphylococcus epidermidis (n = 16), Staphylococcus saprophyticus (n = 4), Staphylococcus hominis (n = 3), Staphylococcus pasteuri (n = 2), Staphylococcus edaphicus (n = 1), and Staphylococcus capitis (n = 1). Biofilm formation was evaluated with a microtiter assay, antibiotic susceptibility testing was performed using the disk diffusion method, and antibiotic resistance and virulence determinants were detected by PCR. Our results showed that all staphylococci produced biofilms and that 92.6% of the isolates were resistant to at least one antibiotic, mainly penicillin (88.8%), fusidic acid (40.7%), and erythromycin (37%). The penicillin resistance gene (blaZ) was detected in 66.6% (18) of the isolates, of which 10 also carried resistance genes to macrolides and lincosamides (mphC, msr(A/B), lnuA, or vgaA), 4 to fusidic acid (fusB), and 3 to trimethoprim-sulfamethoxazole (dfrA). At least one virulence gene (scn, hla, SCCmecIII, and/or SCCmecV) was detected in 48% of the isolates. This study suggests that wild European hake destined for human consumption could act as a vector of CoNS carrying antibiotic resistance genes and/or virulence factors. | 2023 | 38133330 |
| 1266 | 7 | 0.9589 | Characterization of methicillin-resistant coagulase-negative staphylococci in milk from cows with mastitis in Brazil. Staphylococci are one of the most prevalent microorganisms in bovine mastitis. Staphylococcus spp. are widespread in the environment, and can infect animals and humans as opportunistic pathogens. The objective of this study was to determine the frequency of methicillin-resistance (MR) among coagulase-negative staphylococci (CoNS) previously obtained from milk of mastitic cows in Brazil and to characterize the antimicrobial resistance phenotype/genotype and the SCCmec type of MRCoNS isolates. Identification of MRCoNS was based on both biochemical and molecular methods. Susceptibility testing for eleven antimicrobials was performed by disk-diffusion agar. Antimicrobial resistance genes and SCCmec were investigated by specific PCRs. Twenty-six MRCoNS were detected (20 % of total CoNS), obtained from 24 animals, and were identified as follows: S. epidermidis (7 isolates), S. chromogenes (7), S. warneri (6), S. hyicus (5) and S. simulans (1). All MRCoNS isolates carried mecA while the mecC gene was not detected in any CoNS. The SCCmec IVa was demonstrated in nine MRCoNS, while the remaining 17 isolates harbored non-typeable SCCmec cassettes. In addition to oxacillin and cefoxitin resistance, MRCoNS showed resistance to tetracycline (n = 7), streptomycin (n = 6), tobramycin (n = 6), and gentamicin (n = 4), and harbored the genes tet(K) (n = 7), str (n = 3), ant(4') (n = 6) and aac(6')-aph(2″) (n = 4), respectively. In addition, seven strains showed intermediate resistance to clindamycin and two to streptomycin, of which two harboured the lnu(B) and lsa(E) genes and two the aad(E) gene, respectively. One isolate presented intermediate erythromycin and clindamycin resistance and harbored an erm(C) gene with an uncommon 89-bp deletion rendering a premature stop codon. MRCoNS can be implicated in mastitis of cows and they constitute a reservoir of resistance genes that can be transferred to other pathogenic bacteria. | 2014 | 24817534 |
| 5385 | 8 | 0.9585 | Environmental heterogeneity of Staphylococcus species from alkaline fermented foods and associated toxins and antimicrobial resistance genetic elements. Different samples of three products including Bikalga and Soumbala from Burkina Faso (West Africa) and Ntoba Mbodi from Congo-Brazzaville (Central Africa) were evaluated. The bacteria (400) were phenotyped and genotypically characterized by Rep-PCR, PFGE, 16S rRNA and rpoB gene sequencing and spa typing. Their PFGE profiles were compared with those of 12,000 isolates in the Center for Disease Control (CDC, USA) database. They were screened for the production of enterotoxins, susceptibility to 19 antimicrobials, presence of 12 staphylococcal toxin and 38 AMR genes and the ability to transfer erythromycin and tetracycline resistance genes to Enterococcus faecalis JH2-2. Fifteen coagulase negative (CoNS) and positive (CoPS) species characterized by 25 Rep-PCR/PFGE clusters were identified: Staphylococcus arlettae, S. aureus, S. cohnii, S. epidermidis, S. gallinarum, S. haemolyticus, S. hominis, S. pasteuri, S. condimenti, S. piscifermentans, S. saprophyticus, S. sciuri, S. simulans, S. warneri and Macrococcus caseolyticus. Five species were specific to Soumbala, four to Bikalga and four to Ntoba Mbodi. Two clusters of S. gallinarum and three of S. sciuri were particular to Burkina Faso. The S. aureus isolates exhibited a spa type t355 and their PFGE profiles did not match any in the CDC database. Bacteria from the same cluster displayed similar AMR and toxin phenotypes and genotypes, whereas clusters peculiar to a product or a location generated distinct profiles. The toxin genes screened were not detected and the bacteria did not produce the staphylococcal enterotoxins A, B, C and D. AMR genes including blazA, cat501, dfr(A), dfr(G), mecA, mecA1, msr(A) and tet(K) were identified in CoNS and CoPS. Conjugation experiments produced JH2-2 isolates that acquired resistance to erythromycin and tetracycline, but no gene transfer was revealed by PCR. The investigation of the heterogeneity of Staphylococcus species from alkaline fermented foods, their relationship with clinical and environmental isolates and their safety in relation to antimicrobial resistance (AMR) and toxin production is anticipated to contribute to determining the importance of staphylococci in alkaline fermented foods, especially in relation to the safety of the consumers. | 2019 | 31670141 |
| 2091 | 9 | 0.9583 | Antibiotic resistance and virulence profile of Klebsiella pneumoniae isolated from wild Sumatran Orangutans (Pongo abelii). OBJECTIVE: Orangutans (Pongo abelii), as endemic primates of Indonesia, are characterized by a predominantly arboreal lifestyle. Klebsiella pneumoniae (K. pneumonia) and other Gram-negative bacteria are present in the Indigenous flora of many mammals, including orangutans. This study aimed to investigate the antibiotic resistance and virulence profile of K. pneumonia isolated from wild Sumatran orangutans. MATERIALS AND METHODS: This study investigated 10 fecal samples from wild Sumatran orangutans from the Gunung Leuser National Park, Aceh, Indonesia. Biochemical and molecular identification of K. pneumoniae using the RNA polymerase subunit b gene and detection of virulence-associated genes. In addition, molecular detection of antibiotic resistance genes was performed to characterize the resistance mechanisms in the isolates. RESULTS: K. pneumonia was detected in 6 out of 10 fecal samples from wild Sumatran orangutans. The virulence genes mrkD and entB were detected in all (100%) of the isolates, whereas wabG was identified in 83.33% of the strains. Antibiotic susceptibility testing against K. pneumoniae revealed that three isolates were susceptible to streptomycin (S) and nalidixic acid (NA), while all six isolates were susceptible to chloramphenicol and ciprofloxacin. One isolate demonstrated intermediate resistance to NA, while the remaining two exhibited intermediate resistance to S. Six isolates were resistant to ampicillin, tetracycline, and erythromycin, indicating multidrug resistance. Furthermore, antibiotic resistance genes were detected in the isolates with the following prevalence: bla (TEM) gene (six isolates; 100%), bla (SHV) (six isolates; 100%), bla (CTX-M) gene (four isolates; 66.67%), and tetA gene (four isolates; 66.67%). CONCLUSION: This study revealed the virulence and resistance profile of K. pneumoniae bacterium isolated from wild Sumatran orangutans, which is essential for formulating effective conservation and healthcare strategies. | 2024 | 40013287 |
| 1262 | 10 | 0.9583 | Antibiotic Susceptibility and Virulence Genes in Enterococcus Isolates from Wild Mammals Living in Tuscany, Italy. Drug resistance is of great importance to human and animal health, but wild environments are still poorly understood in terms of their function as reservoirs of dangerous microbes and resistance determinants. The aim of the study was to determine the antibiotic susceptibility and virulence factors of Enterococcus bacteria from wildlife in Tuscany, Italy. Of the 36 mammalian fecal samples, 52 isolates were derived and classified as Enterococcus faecium (46% of isolates), Enterococcus hirae (19%), Enterococcus faecalis (13%), Enterococcus gallinarum (8%), Enterococcus casseliflavus (6%), Enterococcus durans (4%), Enterococcus mundtii (2%), and Enterococcus canintestini (2%) using both matrix-assisted laser desorption/ionization-time of flight mass spectrometry and methods based on analysis of genetic material. The isolates tested showed the most frequent resistance to tetracycline (36.5% isolates), ciprofloxacin (36.5%), and erythromycin (25%). Three isolates showed high level of resistance (minimal inhibitory concentration ≥1,024 μg/mL) to vancomycin and teicoplanin, and 15% of the isolates demonstrated multidrug resistance. No isolate resistant to ampicillin, linezolid, or streptomycin was found. Among resistance genes, aac(6)-Ii (50% isolates), msrA/B (48%), msrC (42%), and tetM (31%) were identified most frequently. All E. faecium and E. faecalis isolates were positive for the efaAfm and efaAfs genes, respectively. Other virulence-associated genes, that is, gelE, cylA, asa1, esp, ace, orf1481, ptsD, and sgrA, were found in the majority of E. faecalis and several E. faecium isolates. Multilocus sequence typing analysis performed for selected isolates revealed three new sequence types. The results obtained indicate that wild mammals might act as reservoirs of resistance and virulence determinants that could be transferred between different ecosystems. | 2020 | 31663834 |
| 5395 | 11 | 0.9582 | 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 |
| 5377 | 12 | 0.9580 | Synthetic lincosamides iboxamycin and cresomycin are active against ocular multidrug-resistant methicillin-resistant Staphylococcus aureus carrying erm genes. OBJECTIVE: Antimicrobial resistance is a global pandemic that poses a major threat to vision health as ocular bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA), are becoming increasingly resistant to first-line therapies. Here we evaluated the antimicrobial activity of new synthetic lincosamides in comparison to currently used antibiotics against clinical ocular MRSA isolates. METHODS: Antimicrobial susceptibility testing was performed by broth microdilution for two novel synthetic lincosamides (iboxamycin and cresomycin) and eight comparator antibiotics against a collection of 50 genomically characterised ocular MRSA isolates, including isolates harbouring erm genes (n = 25). RESULTS: Both drugs were active against widespread MRSA clonal complexes CC8 and CC5. The MIC(50) and MIC(90) of iboxamycin were 0.06 and 2 mg/L, respectively. Cresomycin (MIC(50) = 0.06 mg/L) also displayed good activity with an in vitro potency four-fold higher (MIC(90) = 0.5 mg/L) than iboxamycin. In isolates harbouring erm genes, MIC(90) were >16, 2, and 0.5 mg/L for clindamycin, iboxamycin, and cresomycin, respectively. The in vitro potencies of iboxamycin and cresomycin were similar or higher than that of comparator agents and were not impacted by multidrug-resistance phenotypes or by the presence of erm genes when compared with clindamycin. CONCLUSIONS: Our results demonstrate that iboxamycin and cresomycin display potent in vitro activity against ocular MRSA isolates, including multidrug-resistant isolates harbouring erm genes. | 2024 | 39293511 |
| 2991 | 13 | 0.9580 | Occurrence and antimicrobial resistance of Salmonella species and potentially pathogenic Escherichia coli in free-living seals of Canadian Atlantic and eastern Arctic waters. Seal populations in Canadian waters provide sustenance to coastal communities. There is potential for pathogenic and/or antimicrobial-resistant bacteria to transfer to humans through inadvertent faecal contamination of seal products. The objective of this study was to investigate the occurrence and potential antimicrobial resistance of Salmonella spp., Escherichia coli and Listeria monocytogenes in faecal samples collected from grey seals (Halichoerus grypus) in the Gulf of St. Lawrence and from ringed seals (Pusa hispida) in Frobisher Bay and Eclipse Sound, Nunavut, Canada. Grey seals were harvested during commercial hunts or during scientific sampling; ringed seals were collected by Inuit hunters during subsistence harvests. Virulence genes defining pathogenic E. coli were identified by PCR, and antimicrobial susceptibility testing was performed on recovered isolates. In grey seals, E. coli was detected in 34/44 (77%) samples, and pathogenic E. coli (extraintestinal E. coli [ExPEC], enteropathogenic E. coli [EPEC] or ExPEC/EPEC) was detected in 13/44 (29%) samples. Non-susceptibility to beta-lactams and quinolones was observed in isolates from 18 grey seals. In ringed seals from Frobisher Bay, E. coli was detected in 4/45 (9%) samples; neither virulence genes nor antimicrobial resistance was detected in these isolates. In ringed seals from Eclipse Sound, E. coli was detected in 8/50 (16%) samples and pathogenic E. coli (ExPEC and ExPEC/EPEC) in 5/50 (10%) samples. One seal from Eclipse Sound had an E. coli isolate resistant to beta-lactams. A monophasic Salmonella Typhimurium was recovered from 8/50 (16%) seals from Eclipse Sound. All Salmonella isolates were resistant to ampicillin, streptomycin, sulfisoxazole and tetracycline. L. monocytogenes was not detected in any sample. These findings suggest that seals may act as important sentinel species and as reservoirs or vectors for antimicrobial-resistant and virulent E. coli and Salmonella species. Further characterization of these isolates would provide additional insights into the source and spread of antimicrobial resistance and virulence genes in these populations of free-living seals. | 2023 | 37317052 |
| 5414 | 14 | 0.9580 | Genetic determinants of antimicrobial resistance in Gram positive bacteria from organic foods. Bacterial biocide resistance is becoming a matter of concern. In the present study, a collection of biocide-resistant, Gram-positive bacteria from organic foods (including 11 isolates from genus Bacillus, 25 from Enterococcus and 10 from Staphylococcus) were analyzed for genes associated to biocide resistance efflux pumps and antibiotic resistance. The only qac-genes detected were qacA/B (one Bacillus cereus isolate) and smr (one B. cereus and two Staphylococcus saprophyticus isolates). Efflux pump genes efrA and efrB genes were detected in Staphylococcus (60% of isolates), Bacillus (54.54%) and Enterococcus (24%); sugE was detected in Enterococcus (20%) and in one Bacillus licheniformis; mepA was detected in Staphylococcus (60%) and in one Enterococcus isolate (which also carried mdeA), and norE gene was detected only in one Enterococcus faecium and one S. saprophyticus isolate. An amplicon for acrB efflux pump was detected in all but one isolate. When minimal inhibitory concentrations (MICs) were determined, it was found that the addition of reserpine reduced the MICs by eight fold for most of the biocides and isolates, corroborating the role of efflux pumps in biocide resistance. Erythromycin resistance gene ermB was detected in 90% of Bacillus isolates, and in one Staphylococcus, while ereA was detected only in one Bacillus and one Staphyloccus, and ereB only in one Staphylococcus. The ATP-dependent msrA gene (which confers resistance to macrolides, lincosamides and type B streptogramins) was detected in 60% of Bacillus isolates and in all staphylococci, which in addition carried msrB. The lincosamide and streptogramin A resistance gene lsa was detected in Staphylococcus (40%), Bacillus (27.27%) and Enterococcus (8%) isolates. The aminoglycoside resistance determinant aph (3_)-IIIa was detected in Staphylococcus (40%) and Bacillus (one isolate), aph(2_)-1d in Bacillus (27.27%) and Enterococcus (8%), aph(2_)-Ib in Bacillus (one isolate), and the bifunctional aac(6_)1e-aph(2_)-Ia in Staphylococcus (20%), Enterococcus (8%) and Bacillus (one isolate). Chloramphenicol resistance cat gene was detected in Enterococcus (8%) and Staphylococcus (20%), and blaZ only in Staphylococcus (20%). All other antibiotic or biocide resistance genes investigated were not detected in any isolate. Isolates carrying multiple biocide and antibiotic determinants were frequent among Bacillus (36.36%) and Staphylococcus (50%), but not Enterococcus. These results suggest that biocide and antibiotic determinants may be co-selected. | 2014 | 24361832 |
| 1255 | 15 | 0.9579 | Emergence of quinupristin/dalfopristin resistance among livestock-associated Staphylococcus aureus ST9 clinical isolates. Quinupristin/dalfopristin (Q/D) is a valuable alternative to vancomycin for the treatment of meticillin-resistant Staphylococcus aureus (MRSA) infections. However, not long after Q/D was approved, bacteria with resistance to this newer antimicrobial agent were reported. To investigate the prevalence of Q/D resistance, a total of 1476 non-duplicate S. aureus isolates, including 775 MRSA, from a Chinese tertiary hospital were selected randomly from 2003 to 2013. Of the 775 MRSA, 3 (0.4%) were resistant to Q/D. All meticillin-susceptible S. aureus were susceptible to Q/D. The prevalence of Q/D resistance among S. aureus was 0.2% (3/1476). The three isolates with Q/D resistance had the same antimicrobial resistance profile, except for cefaclor and chloramphenicol. All three Q/D-resistant MRSA were positive for five streptogramin B resistance genes (ermA, ermB, ermC, msrA and msrB) and two streptogramin A resistance genes (vatC and vgaA) as determined by PCR and DNA sequencing. MRSA WZ1031 belonged to ST9-MRSA-SCCmecV-t899, whilst MRSA WZ414 and WZ480 belonged to ST9-MRSA-SCCmecNT(non-typeable)-t899. ST9 has been reported predominantly in livestock-associated (LA) MRSA in some Asian countries. The three patients with these MRSA isolates were not livestock handlers and did not keep close contact with livestock. The origin of these important LA-MRSA isolates causing human infections is not known. Taken together, Q/D resistance, which was caused by a combination of ermA-ermB-ermC-msrA-msrB-vatC-vgaA, was first found among S. aureus clinical isolates in China. The present study is the first report of the emergence of human infections caused by ST9 LA-MRSA isolates with Q/D resistance. | 2014 | 25218154 |
| 2405 | 16 | 0.9578 | Coagulase-positive staphylococci isolated from chicken meat: pathogenic potential and vancomycin resistance. Coagulase-positive staphylococci (CPS) cause staphylococcal food poisoning. Recently, these bacteria have received increasing attention due to their potential role in the dissemination of antibiotic resistance markers. The present study aimed to evaluate coagulase-positive staphylococci counts, species distribution, enterotoxin genes prevalence, and the antibiotic resistance profile of CPS isolated from in natura chicken meat. Fifteen frozen and 15 chilled industrialized, uncooked chicken parts or entire carcasses were used. Staphylococcal counts revealed that frozen chicken meat samples displayed the lowest CPS count compared with chilled chicken meat samples (p<0.01). Staphylococcus aureus (62%) was the most common species, followed by S. intermedius, S. delphini, and S. schleiferi subsp. coagulans (10% each) and S. hyicus (8%). The polymerase chain reaction identification of sea, seb, sec, sed, and see genes revealed that 70% of the isolates harbored at least one enterotoxin gene, with sea and sed being the most frequently encountered ones. Two of the 50 investigated strains harbored three different enterotoxin genes. A high frequency of isolates resistant to penicillin, teicoplanin, oxacillin, and clindamycin was observed, and 80% of CPS were found to be resistant to at least one of the 11 tested antimicrobials. Vancomycin-resistant S. aureus and S. intermedius showed minimum inhibitory concentrations of 512 and 64 μg/mL, respectively. These isolates might indicate the dissemination of vancomycin resistance in the community and imply food safety hazards. | 2013 | 23841655 |
| 5387 | 17 | 0.9577 | 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 |
| 1258 | 18 | 0.9577 | Occurrence of antimicrobial resistance and antimicrobial resistance genes in methicillin-resistant Staphylococcus aureus isolated from healthy rabbits. BACKGROUND AND AIM: Methicillin-resistant globally, Staphylococcus aureus (MRSA) is a major cause of disease in both humans and animals. Several studies have documented the presence of MRSA in healthy and infected animals. However, there is less information on MRSA occurrence in exotic pets, especially healthy rabbits. This study aimed to look into the antimicrobial resistance profile, hidden antimicrobial-resistant genes in isolated bacteria, and to estimate prevalence of MRSA in healthy rabbits. MATERIALS AND METHODS: Two-hundreds and eighteen samples, including 42 eyes, 44 ears, 44 oral, 44 ventral thoracic, and 44 perineal swabs, were taken from 44 healthy rabbits that visited the Prasu-Arthorn Animal Hospital, in Nakornpathom, Thailand, from January 2015 to March 2016. The traditional methods of Gram stain, mannitol fermentation, hemolysis on blood agar, catalase test, and coagulase production were used to confirm the presence of Staphylococcus aureus in all specimens. All bacterial isolates were determined by antimicrobial susceptibility test by the disk diffusion method. The polymerase chain reaction was used to identify the antimicrobial-resistant genes (blaZ, mecA, aacA-aphD, msrA, tetK, gyrA, grlA, and dfrG) in isolates of MRSA with a cefoxitin-resistant phenotype. RESULTS: From 218 specimens, 185 S. aureus were isolated, with the majority of these being found in the oral cavity (29.73%) and ventral thoracic area (22.7%), respectively. Forty-seven (25.41%) MRSAs were found in S. aureus isolates, with the majority of these being found in the perineum (16, 34.04%) and ventral thoracic area (13, 27.66%) specimens. Among MRSAs, 29 (61.7%) isolates were multidrug-resistant (MDR) strains. Most of MRSA isolates were resistant to penicillin (100%), followed by ceftriaxone (44.68%) and azithromycin (44.68%). In addition, these bacteria contained the most drug-resistance genes, blaZ (47.83%), followed by gyrA (36.17%) and tetK (23.4%). CONCLUSION: This study revealed that MRSA could be found even in healthy rabbits. Some MRSAs strains were MDR-MRSA, which means that when an infection occurs, the available antibiotics were not effective in treating it. To prevent the spread of MDR-MRSA from pets to owners, it may be helpful to educate owners about effective prevention and hygiene measures. | 2022 | 36590129 |
| 2406 | 19 | 0.9576 | Prevalence of antibiotic resistance genes in staphylococci isolated from ready-to-eat meat products. Prevalence of mecA, blaZ, tetO/K/M, ermA/B/C, aph, and vanA/B/C/D genes conferring resistance to oxacillin, penicillin, tetracycline, erythromycin, gentamicin, and vancomycin was investigated in 65 staphylococcal isolates belonging to twelve species obtained from ready-to-eat porcine, bovine, and chicken products. All coagulase negative staphylococci (CNS) and S. aureus isolates harbored at least one antibiotic resistance gene. None of the S. aureus possessed more than three genes, while 25% of the CNS isolates harbored at least four genes encoding resistance to clinically used antibiotics. In 15 CNS isolates the mecA gene was detected, while all S. aureus isolates were mecA-negative. We demonstrate that in ready-to-eat food the frequency of CNS harboring multiple antibiotic resistance genes is higher than that of multiple resistant S. aureus, meaning that food can be considered a reservoir of bacteria containing genes potentially contributing to the evolution of antibiotic resistance in staphylococci. | 2012 | 22844699 |