PICKED - Word Related Documents




#
Rank
Similarity
Title + Abs.
Year
PMID
012345
122800.9829High Prevalence and Significant Association of ESBL and QNR Genes in Pathogenic Klebsiella pneumoniae Isolates of Patients from Kolkata, India. Pathogenic Klebsiella pneumoniae, resistant to beta-lactam and quinolone drugs, is widely recognized as important bacteria causing array of diseases. The resistance property is obtained by acquisition of plasmid encoded blaTEM, blaSHV, blaCTX-M, QNRA, QNRB and QNRS genes. The aim of this study was to document the prevalence and association of these resistant genes in K. pneumoniae infecting patients in India. Approximately 97 and 76.7 % of the 73 K. pneumoniae isolates showed resistance towards beta-lactam and quinolone drugs respectively. Bla genes were detected in 74 % of K. pneumoniae isolates; with prevalence in the following order: blaTEM > blaSHV > blaCTXM. QNR genes were detected in 67 % samples. Chi-square analysis revealed significant association between presence of bla and qnr genes in our study (P value = 0.000125). Sequence analysis of some blaTEM, blaSHV, blaCTX-M and QNRB PCR products revealed presence of blaTEM1 (GenBank accession: JN193522), blaTEM116 (JN193523 and JN193524), blaSHV11, blaCTXM72 variants (JF523199) and QNRB1 (JN193526 and JN193527) in our samples.201224293710
304710.9821Formaldehyde-resistance in Enterobacteriaceae and Pseudomonas aeruginosa: identification of resistance genes by DNA-hybridization. A 4.1. Kb large DNA fragment of a E. coli plasmid pVU 3695, on which the genes for formaldehyde-resistance are located, was used as a DNA probe to identify bacteria that carry this segment among formaldehyde-resistant bacteria. It was shown by Southern Blot-, Dot Blot-, and Colony Blot- Hybridization studies that the DNA of all formaldehyde-resistant E. coli, Serratia marcescens, Enterobacter cloacae, Citrobacter freundii and Klebsiella pneumoniae strains tested hybridize with the DNA probe from E. coli. In contrast the E. coli DNA probe does not hybridize with the DNA from formaldehyde-resistant Pseudomonas aeruginosa strains.19911909132
121420.9818Plasmid-mediated quinolone resistance genes in fecal bacteria from rooks commonly wintering throughout Europe. This study concerned the occurrence of fecal bacteria with plasmid-mediated quinolone resistance (PMQR) genes in rooks (Corvus frugilegus, medium-sized corvid birds) wintering in continental Europe during winter 2010/2011. Samples of fresh rook feces were taken by cotton swabs at nine roosting places in eight European countries. Samples were transported to one laboratory and placed in buffered peptone water (BPW). The samples from BPW were enriched and subcultivated onto MacConkey agar (MCA) supplemented with ciprofloxacin (0.06 mg/L) to isolate fluoroquinolone-resistant bacteria. DNA was isolated from smears of bacterial colonies growing on MCA and tested by PCR for PMQR genes aac(6')-Ib, qepA, qnrA, qnrB, qnrC, qnrD, qnrS, and oqxAB. All the PCR products were further analyzed by sequencing. Ciprofloxacin-resistant bacteria were isolated from 37% (392 positive/1,073 examined) of samples. Frequencies of samples with ciprofloxacin-resistant isolates ranged significantly from 3% to 92% in different countries. The qnrS1 gene was found in 154 samples and qnrS2 in 2 samples. The gene aac(6')-Ib-cr was found in 16 samples. Thirteen samples were positive for qnrB genes in variants qnrB6 (one sample), qnrB18 (one), qnrB19 (one), qnrB29 (one), and qnrB49 (new variant) (one). Both the qnrD and oqxAB genes were detected in six samples. The genes qnrA, qnrC, and qepA were not found. Wintering omnivorous rooks in Europe were commonly colonized by bacteria supposedly Enterobacteriaceae with PMQR genes. Rooks may disseminate these epidemiologically important bacteria over long distances and pose a risk for environmental contamination.201222731858
106530.9817Predominance of multi-drug resistant extended spectrum β lactamase producing bacteria from marine fishes. The present study aimed to determine the extended spectrum beta lactamase (ESBL) genes in the bacteria from fresh exportable fish samples collected along South east coast of India, Chennai. ESBL genes are the base for the antibiotic resistance in pathogens and it transmitted from one to other species. Totally 2670 isolates were isolated from 293 fish samples which belong to 31 species dominated by Aeromonas, Klebsiella, Serratia, Leclerica, Proteus, Enterobacter, Acinetobacter, Haemophilus, Escherichia, Shigella sp. Out of 2670 isolates, 1958 isolates have multi drug resistant capacity with ESBL genes of bla(CTX), bla(SHV), bla(TEM) and bla(AmpC) and 712 isolates are not detected ESBL genes. The present study revealed that, the contamination of fresh fish sample with pathogenic bacteria resistant to multiple antibiotics can incriminate seafood as a potential carrier and accentuate an immediate need to prevent environmental infectivity and distribution. Further, hygienic facilitated markets should be developed with ensured quality of seafood.202336813100
139140.9815Faecal carriage of extended-spectrum β-lactamase-producing and AmpC β-lactamase-producing bacteria among Danish army recruits. During May and June 2008, 84 Danish army recruits were tested for faecal carriage of extended-spectrum β-lactamase (ESBL)-producing and AmpC β-lactamase-producing bacteria. Three ESBL-producing (CTX-M-14a) Escherichia coli isolates, two AmpC-producing (CMY-2) E. coli isolates and one AmpC-producing (CMY-34) Citrobacter freundii isolate were detected. Two of the CTX-M-14a E. coli isolates had similar pulsed-field gel electrophoresis and multilocus sequence typing profiles, indicating the same origin or transmission between the two army recruits. The bla(CTX-M-14a) genes were transferable to an E. coli recipient. These commensal bacteria therefore constitute a reservoir of resistance genes that can be transferred to other pathogenic bacteria in the intestine.201120718802
83150.9812RmtC and RmtF 16S rRNA Methyltransferase in NDM-1-Producing Pseudomonas aeruginosa. We investigated 16S rRNA methyltransferases in 38 blaNDM-1-positive Pseudomonas aeruginosa isolates and found RmtC in 3 isolates, 1 of which also harbored RmtF. The isolates were clonally unrelated; rmtC and rmtF genes were located on a chromosome with the blaNDM-1 gene. Strategies are needed to limit the spread of such isolates.201526488937
304860.9811Colicin production/resistance associated with R-plasmids of Gram negative bacteria isolated from poultry in Karachi. R plasmids of Gram negative bacteria isolated from poultry in Karachi were studied for their properties of colicin production and resistance. Of 39 R plasmids studied, 23 resisted colicin where as only one R-plasmid produced colicin.199816414807
118770.9809Coastal seawater bacteria harbor a large reservoir of plasmid-mediated quinolone resistance determinants in Jiaozhou Bay, China. Diversity and prevalence of plasmid-mediated quinolone resistance determinants were investigated in environmental bacteria isolated from surface seawater of Jiaozhou Bay, China. Five qnr gene alleles were identified in 34 isolates by PCR amplification, including qnrA3 gene in a Shewanella algae isolate, qnrB9 gene in a Citrobacter freundii isolate, qnrD gene in 22 Proteus vulgaris isolates, qnrS1 gene in 1 Enterobacter sp. and 4 Klebsiella spp. isolates, and qnrS2 gene in 1 Pseudomonas sp. and 4 Pseudoalteromonas sp. isolates. The qnrC, aac(6')-Ib-cr, and qepA genes could not be detected in this study. The 22 qnrD-positive Proteus vulgaris isolates could be differentiated into four genotypes based on ERIC-PCR assay. The qnrS1 and qnrD genes could be transferred to Escherichia coli J53 Azi(R) or E. coli TOP10 recipient strains using conjugation or transformation methods. Among the 34 qnr-positive isolates, 30 had a single point mutation in the QRDRs of GyrA protein (Ala67Ser, Ser83Ile, or Ser83Thr), indicating that cooperation of chromosome- and plasmid-mediated resistance contributed to the spread and evolution of quinolone resistance in this coastal bay. Eighty-five percent of the isolates were also found to be resistant to ampicillin, and bla(CMY), bla(OXY), bla(SHV), and bla(TEM) genes were detected in five isolates that also harbored the qnrB9 or qnrS1 gene. Our current study is the first identification of qnrS2 gene in Pseudoalteromonas and Pseudomonas strains, and qnrD gene in Proteus vulgaris strains. High prevalence of diverse qnr genes in Jiaozhou Bay indicates that coastal seawater may serve as an important reservoir, natural source, and dissemination vehicle of quinolone resistance determinants.201222252223
612780.9809Paenibacillus associated with milky disease in Central and South American scarabs. Thirty-one isolates of bacteria causing milky disease in scarab larvae collected in Central and South America were identified as Paenibacillus popilliae or Paenibacillus lentimorbus by use of DNA similarity analysis. The isolates were more similar to each other than to the North American isolates that are the type strains of the species. All of the bacteria of both species produced parasporal bodies, a characteristic previously believed to be unique to P. popilliae. Screening of the bacteria using PCR with parasporal protein primers revealed differences among the parasporal protein genes of P. popilliae isolates and between the parasporal genes of P. popilliae and P. lentimorbus. In contrast to P. popilliae from North America, none of the isolates from Central and South America was resistant to vancomycin, an indication of an interesting geographic distribution of the resistance genes.200011023744
117590.9808Existence of a novel qepA variant in quinolone resistant Escherichia coli from aquatic habitats of Bangladesh. Of 19 environmental Escherichia coli (n = 12) and Klebsiella pneumoniae (n = 7) tested for quinolone resistance-related genes qnrA, qnrB, qnrC, qnrS and qepA, four each of E. coli and K. pneumoniae possessed qnrS, and another E. coli isolate possessed a new variant of qepA. This is the first detection of qepA in environmentally dwelling bacteria in Bangladesh.201729075330
1173100.9807Investigation of plasmid-mediated quinolone resistance in Pseudomonas aeruginosa clinical isolates. AIMS: To investigate plasmid-mediated quinolone resistance in clinical isolates of Pseudomonas aeruginosa with the polymerase chain reaction (PCR). The plasmid-mediated quinolone resistance genes have been identified in many bacteria within the Enterobactericeae family, they have not been detected in P. aeruginosa isolates. Subjects and Methods : Identification of the isolates and testing of antibiotic susceptibility was performed in Vitek2 Compact (Biomeriux, France) and Phoinex (BD, USA) automated systems. Screening for the qnrA, qnrB, qnrS, qnrC, aac (6')-Ib-cr and qepA genes was carried out by PCR amplification and aac (6')-Ib-cr DNA sequencing. RESULTS: The qnr and the qepA genes were not detected in any of P. aeruginosa isolates. The aac (6')-Ib gene was detected in six of the isolates and positive isolates for aac (6')-Ib were sequenced for detection of the aac (6')-Ib-cr variant but aac (6')-Ib-cr was not detected in any isolates. CONCLUSIONS: Plasmid-mediated quinolone resistance genes have so far not been identified in P. aeruginosa isolates. However, qnrB have detected in P. florescens and P. putida isolates. This is the first study conducted on the qnrA, qnrB, qnrS and qnrC genes as well as the qepA and aac (6')-Ib-cr genes in P. aeruginosa clinical isolates.201425008822
1174110.9807Identification of plasmid-mediated quinolone resistance qnr genes in multidrug-resistant Gram-negative bacteria from hospital wastewaters and receiving waters in the Jinan area, China. We investigated the prevalence of plasmid-mediated quinolone resistance (PMQR) qnr genes by the polymerase chain reaction (PCR) in antibiotic-resistant bacteria isolates collected from aquatic environments in Jinan during 2 years (2008.3-2009.11). Genes were identified to variant level by PCR restriction fragment length polymorphism analysis or sequencing. qnrA1, qnrB2, qnrB4, qnrB6, qnrB9, qnrS1, and the new qnrB variant qnrB26 were detected in 31 strains from six genera (Klebsiella spp., Escherichia coli, Enterobacter spp., Proteus spp., Shigella spp., and Citrobacter spp.), four of which contained double qnr genes. Other PMQR genes, aac(6')-Ib-cr and qepA, were found in 12 (38.7%) and 5 (16.1%) of 31 isolates, respectively; while qepA was found in Shigella spp. for the first time. Eight types of β-lactamase genes and eight other types of resistance genes were also present in the 31 qnr-positive isolates. The detection rate for five β-lactamase genes (blaTEM, blaCTX, ampR, blaDHA, and blaSHV) was >45%. Class 1 integrons and complex class 1 integrons were prevalent in these strains, which contained 15 different gene cassette arrays and 5 different insertion sequence common region 1 (ISCR1)-mediated downstream structures. qnrA1, qnrB2, and qnrB6 were present in three ISCR1-mediated downstream structures: qnrA1-ampR, sapA-like-qnrB2, and sdr-qnrB6. We also analyzed the horizontal transferability of PMQR genes and other resistance determinants. The qnr genes and some integrons and resistance genes from 18 (58.1%) of the 31 qnr-positive strains could be transferred to E. coli J53 Azi(R) or E. coli DH5α recipient strains using conjugation or transformation methods. The results showed that a high number of qnr genes were associated with other resistance genes in aquatic environments in Jinan. This suggests that we should avoid over-using antibiotics and monitor aquatic environments to control the spread of antibiotic resistance genes.201323844849
5856120.9807Amplification of DNA from native populations of soil bacteria by using the polymerase chain reaction. Specific DNA sequences from native bacterial populations present in soil, sediment, and sand samples were amplified by using the polymerase chain reaction with primers for either "universal" eubacterial 16S rRNA genes or mercury resistance (mer) genes. With standard amplification conditions, 1.5-kb rDNA fragments from all 12 samples examined and from as little as 5 micrograms of soil were reproducibly amplified. A 1-kb mer fragment from one soil sample was also amplified. The identity of these amplified fragments was confirmed by DNA-DNA hybridization.19921444376
366130.9807Genes encoding mercuric reductases from selected gram-negative aquatic bacteria have a low degree of homology with merA of transposon Tn501. An investigation of the Hg2+ resistance mechanism of four freshwater and four coastal marine bacteria that did not hybridize with a mer operonic probe was conducted (T. Barkay, C. Liebert, and M. Gillman, Appl. Environ. Microbiol. 55:1196-1202, 1989). Hybridization with a merA probe, the gene encoding the mercuric reductase polypeptide, at a stringency of hybridization permitting hybrid formation between evolutionarily distant merA genes (as exists between gram-positive and -negative bacteria), detected merA sequences in the genomes of all tested strains. Inducible Hg2+ volatilization was demonstrated for all eight organisms, and NADPH-dependent mercuric reductase activities were detected in crude cell extracts of six of the strains. Because these strains represented random selections of bacteria from three aquatic environments, it is concluded that merA encodes a common molecular mechanism for Hg2+ resistance and volatilization in aerobic heterotrophic aquatic communities.19902166470
3042140.9807Aminoglycoside acetyltransferase 3-IV (aacC4) and hygromycin B 4-I phosphotransferase (hphB) in bacteria isolated from human and animal sources. Members of the family Enterobacteriaceae harboring an enzyme of the aminoglycoside acetyltransferase 3 class (AAC-3-IV) (apramycin and gentamicin resistance) and hygromycin B phosphotransferase 4 (HPH-4-I) (hygromycin B resistance) have been isolated from human clinical sources in Europe. A cluster of genes containing IS140, aacC4, and hphB was found in these strains. We demonstrate by Southern hybridization that this cluster is identical to the operon found in animals that also contains insertion sequences belonging to the ISO family. This provides another example of presumptive transfer of antibiotic resistance genes between bacteria of animal and human origin.19901963287
1385150.9806GENOMIC CHARACTERIZATION OF MULTIDRUG-RESISTANT EXTENDED-SPECTRUM β-LACTAMASE-PRODUCING ESCHERICHIA COLI AND KLEBSIELLA PNEUMONIAE FROM CHIMPANZEES (PAN TROGLODYTES) FROM WILD AND SANCTUARY LOCATIONS IN UGANDA. Farm and wild animals may serve as reservoirs of antimicrobial-resistant bacteria of human health relevance. We investigated the occurrence and genomic characteristics of extended spectrum β-lactamase (ESBL)-producing bacteria in Ugandan chimpanzees (Pan troglodytes) residing in two environments with or without close contact to humans. The ESBL-producing Escherichia coli and Klebsiella pneumoniae were isolated from fecal material of chimpanzees from Budongo Forest and Ngamba Island Chimpanzee Sanctuary in Uganda and were more commonly isolated from chimpanzees in Ngamba Island Chimpanzee Sanctuary, where animals have close contact with humans. Selected ESBL isolates (E. coli n=9, K. pneumoniae n=7) were analyzed by whole-genome sequencing to determine the presence of resistance genes, as well as sequence type and virulence potential; the blaCTX-M-15 gene was present in all strains. Additionally, the ESBL genes blaSHV-11 and blaSHV-12 were found in strains in the study. All strains were found to be multidrug resistant. The E. coli strains belonged to four sequence types (ST2852, ST215, ST405, and ST315) and the K. pneumoniae strains to two sequence types (ST1540 and ST597). Virulence genes did not indicate that strains were of common E. coli pathotype, but strains with the same sequence types as isolated in the current study have previously been reported from clinical cases in Africa. The findings indicate that chimpanzees in close contact with humans may carry ESBL bacteria at higher frequency than those in the wild, indicating a potential anthropogenic transmission.202235255126
2618160.9806The profile of antibiotics resistance and integrons of extended-spectrum beta-lactamase producing thermotolerant coliforms isolated from the Yangtze River basin in Chongqing. The spreading of extended-spectrum beta-lactamases (ESBL)-producing thermotolerant coliforms (TC) in the water environment is a threat to human health but little is known about ESBL-producing TCs in the Yangtze River. We received 319 ESBL-producing stains obtained from the Chongqing basin and we investigated antibiotic susceptibility, bla gene types and the presence of integrons and gene cassettes. 16.8% of TC isolates were ESBL-producing bacteria and bla(TEM+CTx-M) was the predominant ESBL type. 65.2% of isolates contained class 1 integrons, but only 3 carried intI 2. Gene cassettes were amplified and sequenced. aadA, drfA, cmlA, sat1, aar3 and two ORF cassettes were found. In conclusion, Yangtze River is heavily polluted by ESBL-producing TC bacteria and the combined bla gene type could enhance antibiotic resistance. Class 1 integrons were widespread in ESBL-producing isolates and play an important role in multi-drug resistance. Characterization of gene cassettes could reveal the dissemination of antibiotic resistance genes.201020447743
2011170.9806Molecular epidemiology of two genes encoding 3-N-aminoglycoside acetyltransferases AAC(3)I and AAC(3)II among gram-negative bacteria from a Spanish hospital. The molecular epidemiology of the aacC1 and aacC2 genes, encoding 3-N-aminoglycoside acetyltransferases AAC(3)I and AAC(3)II, respectively, was studied by DNA-DNA hybridization. The sample included 315 gentamicin-resistant Gram-negative bacilli collected over a six-month period from patients attending a Spanish Hospital. The aminoglycoside resistance phenotype of these strains was also determined. The aacC1 probe hybridized with 39 strains, the aacC2 probe with 146 strains and both probes hybridized with 26 strains. The aacC1 gene was most frequently detected in Pseudomonas aeruginosa whereas the aacC2 gene was most frequently detected in enterobacteria and Acinetobacter spp. Strains harbouring aacC genes were isolated from both in- and outpatients with different infectious diseases, mainly urinary tract infections. As inferred from the results of Southern hybridization, both genes showed a wide horizontal dispersion among plasmids and bacteria.19938150069
1063180.9806Enterobacteriaceae resistant to third-generation cephalosporins and quinolones in fresh culinary herbs imported from Southeast Asia. Since multidrug resistant bacteria are frequently reported from Southeast Asia, our study focused on the occurrence of ESBL-producing Enterobacteriaceae in fresh imported herbs from Thailand, Vietnam and Malaysia. Samples were collected from fresh culinary herbs imported from Southeast Asia in which ESBL-suspected isolates were obtained by selective culturing. Analysis included identification by MALDI-TOF mass spectrometry, susceptibility testing, XbaI-PFGE, microarray, PCR and sequencing of specific ESBL genes, PCR based replicon typing (PBRT) of plasmids and Southern blot hybridization. In addition, the quinolone resistance genotype was characterized by screening for plasmid mediated quinolone resistance (PMQR) genes and mutations in the quinolone resistance determining region (QRDR) of gyrA and parC. The study encompassed fifty samples of ten batches of culinary herbs (5 samples per batch) comprising nine different herb variants. The herbs originated from Thailand (Water morning glory, Acacia and Betel leaf), Vietnam (Parsley, Asian pennywort, Houttuynia leaf and Mint) and Malaysia (Holy basil and Parsley). By selective culturing 21 cefotaxime resistant Enterobacteriaceae were retrieved. Array analysis revealed 18 isolates with ESBL genes and one isolate with solely non-ESBL beta-lactamase genes. Mutations in the ampC promoter region were determined in two isolates with PCR and sequencing. The isolates were identified as Klebsiella pneumoniae (n=9), Escherichia coli (n=6), Enterobacter cloacae complex (n=5) and Enterobacter spp. (n=1). All isolates tested were multidrug resistant. Variants of CTX-M enzymes were predominantly found followed by SHV enzymes. PMQR genes (including aac(6')-1b-cr, qnrB and qnrS) were also frequently detected. In almost all cases ESBL and quinolone resistance genes were located on the same plasmid. Imported fresh culinary herbs from Southeast Asia are a potential source for contamination of food with multidrug resistant bacteria. Because these herbs are consumed without appropriate heating, transfer to human bacteria cannot be excluded.201424607424
367190.9806Translocatable resistance to mercuric and phenylmercuric ions in soil bacteria. Of a sample of 42 gram-negative Hg-resistant bacteria, three (a Pseudomonas fluorescens, a Klebsiella sp. and a Citrobacter sp.) contained translocatable elements conferring resistance to Hg2+ (all three) and to Hg2+ and phenylmercuric acetate (P. fluorescens). The discovery of transposable phenylmercuric acetate resistance extends the range of known resistance "transposons" from heavy metals and antibiotics to organometallic compounds.19816268601